TABLE OF CONTENTS

Prospectus

Through and including April 16, 2018 (the 25th day after the date of this prospectus), all dealers effecting transactions in these securities, whether or not participating in this offering, may be required to deliver a prospectus. This is in addition to a dealer’s obligation to deliver a prospectus when acting as an underwriter and with respect to an unsold allotment or subscription.

Neither we, the selling stockholders, nor any of the underwriters have authorized anyone to provide any information or to make any representations other than those contained in this prospectus or in any free writing prospectuses we have prepared. Neither we, the selling stockholders, nor any of the underwriters take responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus is an offer to sell only the shares offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus is current only as of its date, regardless of the time of delivery of this prospectus or of any sale of our Class A common stock.

For investors outside the United States: Neither we, the selling stockholders, nor any of the underwriters have done anything that would permit our initial public offering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of the shares of our Class A common stock and the distribution of this prospectus outside the United States.

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RISK FACTORS

Investing in our Class A common stock involves a high degree of risk. You should consider carefully the risks and uncertainties described below, together with all of the other information in this prospectus, including the section titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and our consolidated financial statements and related notes, before making a decision to invest in our Class A common stock. Our business, results of operations, financial condition, or prospects could also be harmed by risks and uncertainties that are not presently known to us or that we currently believe are not material. If any of the risks actually occur, our business, results of operations, financial condition, and prospects could be materially and adversely affected. In that event, the market price of our Class A common stock could decline, and you could lose all or part of your investment.

Risks Related to Our Business and Our Industry

Our business depends on our ability to retain and upgrade paying users, and any decline in renewals or upgrades could adversely affect our future results of operations.

Our business depends upon our ability to maintain and expand our relationships with our users. Our business is subscription based, and paying users are not obligated to and may not renew their subscriptions after their existing subscriptions expire. As a result, we cannot provide assurance that paying users will renew their subscriptions utilizing the same tier of our products or upgrade to premium offerings. Renewals of subscriptions to our platform may decline or fluctuate because of several factors, such as dissatisfaction with our products and support, a user no longer having a need for our products, or the perception that competitive products provide better or less expensive options. In addition, some paying users downgrade or do not renew their subscriptions.

We encourage paying users to upgrade to our premium offerings by recommending additional features and through in-product prompts and notifications. Additionally, we seek to expand within organizations through viral means by adding new users, having workplaces purchase additional products, or expanding the use of Dropbox into other departments within a workplace. We often see enterprise IT decision-makers deciding to adopt Dropbox after noticing substantial organic adoption by individuals and teams within the organization. If our paying users fail to renew or cancel their subscriptions, or if we fail to upgrade our paying users to premium offerings or expand within organizations, our business, results of operations, and financial condition may be harmed.

Although it is important to our business that our users renew their subscriptions after their existing subscriptions expire and that we expand our commercial relationships with our users, given the volume of our users, we do not track the retention rates of our individual users. As a result, we may be unable to address any retention issues with specific users in a timely manner, which could harm our business.

Our future growth could be harmed if we fail to attract new users or convert registered users to paying users.

We must continually add new users to grow our business beyond our current user base and to replace users who choose not to continue to use our platform. Historically, our revenue has been driven by our self-serve model, and we generate more than 90% of our revenue from self-serve channels. Any decrease in user satisfaction with our products or support could harm our brand, word-of-mouth referrals, and ability to grow.

Additionally, many of our users initially access our platform free of charge. We strive to demonstrate the value of our platform to our registered users, thereby encouraging them to convert to paying users through in-product prompts and notifications, and time-limited trials of paid subscription plans. As of December 31, 2017, we served over 500 million registered users but only 11 million paying users. The actual number of unique users is lower than we report as one person may register more than once for our platform. As a result, we have fewer unique registered users that we may be able to convert to paying users. A majority of our registered users may never convert to a paid subscription to our platform.

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In addition, our user growth rate may slow in the future as our market penetration rates increase and we turn our focus to converting registered users to paying users rather than growing the total number of registered users. If we are not able to continue to expand our user base or fail to convert our registered users to paying users, demand for our paid services and our revenue may grow more slowly than expected or decline.

Our revenue growth rate has declined in recent periods and may continue to slow in the future.

We have experienced significant revenue growth in prior periods. However, our rates of revenue growth are slowing and may continue to slow in the future. Many factors may contribute to declines in our growth rates, including higher market penetration, increased competition, slowing demand for our platform, a decrease in the growth of the overall content collaboration market, a failure by us to continue capitalizing on growth opportunities, and the maturation of our business, among others. You should not rely on the revenue growth of any prior quarterly or annual period as an indication of our future performance. If our growth rates decline, investors’ perceptions of our business and the trading price of our Class A common stock could be adversely affected.

We have a history of net losses, we anticipate increasing expenses in the future, and we may not be able to achieve or maintain profitability.

We have incurred net losses on an annual basis since our inception. We incurred net losses of $325.9 million, $210.2 million, and $111.7 million in 2015, 2016, and 2017, respectively, and we had an accumulated deficit of $1,049.7 million as of December 31, 2017. As we strive to grow our business, we expect expenses to increase in the near term, particularly as we continue to make investments to scale our business. For example, we will need an increasing amount of technical infrastructure to continue to satisfy the needs of our user base. We also expect our research and development expenses to increase as we plan to continue to hire employees for our engineering, product, and design teams to support these efforts. In addition, we will incur additional rent expense in connection with our move to our new corporate headquarters, and additional general and administrative expenses to support both our growth as well as our transition to being a publicly traded company. These investments may not result in increased revenue or growth in our business. We may encounter unforeseen or unpredictable factors, including unforeseen operating expenses, complications, or delays, which may result in increased costs. Furthermore, it is difficult to predict the size and growth rate of our market, user demand for our platform, user adoption and renewal of our platform, the entry of competitive products and services, or the success of existing competitive products and services. As a result, we may not achieve or maintain profitability in future periods. If we fail to grow our revenue sufficiently to keep pace with our investments and other expenses, our results of operations and financial condition would be adversely affected.

Our business could be damaged, and we could be subject to liability if there is any unauthorized access to our data or our users’ content, including through privacy and data security breaches.

The use of our platform involves the transmission, storage, and processing of user content, some of which may be considered personally identifiable, confidential, or sensitive. We face security threats from malicious third parties that could obtain unauthorized access to our systems and networks. We anticipate that these threats will continue to grow in scope and complexity over time. For example, in 2016, we learned that an old set of Dropbox user credentials for approximately 68 million accounts was released. These credentials consisted of email addresses and passwords protected by cryptographic techniques known as hashing and salting. Hashing and salting can make it more difficult to obtain the original password, but may not fully protect the original password from being obtained. We believe these Dropbox user credentials were obtained in 2012 and related to a security incident we disclosed to users. In response, we notified all existing users we believed to be affected and completed a password reset for anyone who had not updated their password since mid-2012. We have responded to this event by expanding our security team and data monitoring capabilities and continuing to work on features such as two-factor authentication to increase protection of user information. While we believe our corrective actions will reduce the likelihood of similar incidents occurring in the future, third parties might use techniques

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that we are unable to defend against to compromise and infiltrate our systems and networks. We may fail to detect the existence of a breach of user content and be unable to prevent unauthorized access to user and company content. The techniques used to obtain unauthorized access, disable or degrade service, or sabotage systems change frequently and are often not recognized until launched against a target. They may originate from less regulated or remote areas around the world, or from state-sponsored actors. If our security measures are breached, or our users’ content is otherwise accessed through unauthorized means, or if any such actions are believed to occur, our platform may be perceived as insecure, and we may lose existing users or fail to attract and retain new users.

We may rely on third parties when deploying our infrastructure, and in doing so, expose it to security risks outside of our direct control. We rely on outside vendors and contractors to perform services necessary for the operation of the business, and they may fail to adequately secure our user and company content.

Third parties may attempt to compromise our employees and their privileged access into internal systems to gain access to accounts, our information, our networks, or our systems. Employee error, malfeasance, or other errors in the storage, use, or transmission of personal information could result in an actual or perceived breach of user privacy. Our users may also disclose or lose control of their passwords, or use the same or similar passwords on third parties’ systems, which could lead to unauthorized access to their accounts on our platform.

Any unauthorized or inadvertent access to, or an actual or perceived security breach of, our systems or networks could result in an actual or perceived loss of, or unauthorized access to, our data or our users’ content, regulatory investigations and orders, litigation, indemnity obligations, damages, penalties, fines, and other costs in connection with actual and alleged contractual breaches, violations of applicable laws and regulations, and other liabilities. Any such incident could also materially damage our reputation and harm our business, results of operations, and financial condition, including reducing our revenue, causing us to issue credits to users, negatively impacting our ability to accept and process user payment information, eroding our users’ trust in our services and payment solutions, subjecting us to costly user notification or remediation, harming our ability to retain users, harming our brand, or increasing our cost of acquiring new users. We maintain errors, omissions, and cyber liability insurance policies covering certain security and privacy damages. However, we cannot be certain that our coverage will be adequate for liabilities actually incurred or that insurance will continue to be available to us on economically reasonable terms, or at all. Further, if a high profile security breach occurs with respect to another content collaboration solutions provider, our users and potential users could lose trust in the security of content collaboration solutions providers generally, which could adversely impact our ability to retain users or attract new ones.

Our business could be harmed by any significant disruption of service on our platform or loss of content.

Our brand, reputation, and ability to attract, retain, and serve our users are dependent upon the reliable performance of our platform, including our underlying technical infrastructure. Our users rely on our platform to store digital copies of their valuable content, including financial records, business information, documents, photos, and other important content. Our technical infrastructure may not be adequately designed with sufficient reliability and redundancy to avoid performance delays or outages that could be harmful to our business. If our platform is unavailable when users attempt to access it, or if it does not load as quickly as they expect, users may not use our platform as often in the future, or at all.

As our user base and the amount and types of information stored, synced, and shared on our platform continues to grow, we will need an increasing amount of technical infrastructure, including network capacity and computing power, to continue to satisfy the needs of our users. During 2015 and 2016, we migrated the vast majority of user content to our own custom-built infrastructure in co-location facilities that we directly lease and operate. As we add to our infrastructure, we may move or transfer additional content.

Further, as we continue to grow and scale our business to meet the needs of our users, we may overestimate or underestimate our infrastructure capacity requirements, which could adversely affect our results of operations.

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The costs associated with leasing and maintaining our custom-built infrastructure in co-location facilities and third-party datacenters already constitute a significant portion of our capital and operating expenses. We continuously evaluate our short- and long-term infrastructure capacity requirements to ensure adequate capacity for new and existing users while minimizing unnecessary excess capacity costs. If we overestimate the demand for our platform and therefore secure excess infrastructure capacity, our operating margins could be reduced. If we underestimate our infrastructure capacity requirements, we may not be able to service the expanding needs of new and existing users, and our hosting facilities, network, or systems may fail.

In addition, the datacenters that we use are vulnerable to damage or interruption from human error, intentional bad acts, earthquakes, floods, fires, war, terrorist attacks, power losses, hardware failures, systems failures, telecommunications failures, and similar events, any of which could disrupt our service, destroy user content, or prevent us from being able to continuously back up or record changes in our users’ content. In the event of significant physical damage to one of these datacenters, it may take a significant period of time to achieve full resumption of our services, and our disaster recovery planning may not account for all eventualities. Damage or interruptions to these datacenters could harm our platform and business.

We generate revenue from sales of subscriptions to our platform, and any decline in demand for our platform or for content collaboration solutions in general could negatively impact our business.

We generate, and expect to continue to generate, revenue from the sale of subscriptions to our platform. As a result, widespread acceptance and use of content collaboration solutions in general, and our platform in particular, is critical to our future growth and success. If the content collaboration market fails to grow or grows more slowly than we currently anticipate, demand for our platform could be negatively affected.

Changes in user preferences for content collaboration may have a disproportionately greater impact on us than if we offered multiple platforms or disparate products. Demand for content collaboration solutions in general, and our platform in particular, is affected by a number of factors, many of which are beyond our control. Some of these potential factors include:

The content collaboration market is subject to rapidly changing user demand and trends in preferences. If we fail to successfully predict and address these changes and trends, meet user demands, or achieve more widespread market acceptance of our platform, our business, results of operations, and financial condition could be harmed.

Our business depends upon the interoperability of our platform across devices, operating systems, and third-party applications that we do not control.

One of the most important features of our platform is its broad interoperability with a range of diverse devices, operating systems, and third-party applications. Our platform is accessible from the web and from

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devices running Windows, Mac OS, iOS, Android, WindowsMobile, and Linux. We also have integrations with Microsoft, Adobe, Apple, Salesforce, Atlassian, Slack, IBM, Cisco, VMware, Okta, Symantec, Palo Alto Networks, and a variety of other productivity, collaboration, data management, and security vendors. We are dependent on the accessibility of our platform across these third-party operating systems and applications that we do not control. Several of our competitors own, develop, operate, or distribute operating systems, app stores, third-party datacenter services, and other software, and also have material business relationships with companies that own, develop, operate, or distribute operating systems, applications markets, third-party datacenter services, and other software that our platform requires in order to operate. Moreover, some of these competitors have inherent advantages developing products and services that more tightly integrate with their software and hardware platforms or those of their business partners.

Third-party services and products are constantly evolving, and we may not be able to modify our platform to assure its compatibility with that of other third parties following development changes. In addition, some of our competitors may be able to disrupt the operations or compatibility of our platform with their products or services, or exert strong business influence on our ability to, and terms on which we, operate and distribute our platform. For example, we currently offer products that directly compete with several large technology companies that we rely on to ensure the interoperability of our platform with their products or services. As our respective products evolve, we expect this level of competition to increase. Should any of our competitors modify their products or standards in a manner that degrades the functionality of our platform or gives preferential treatment to competitive products or services, whether to enhance their competitive position or for any other reason, the interoperability of our platform with these products could decrease and our business, results of operations, and financial condition could be harmed.

We operate in competitive markets, and we must continue to compete effectively.

The market for content collaboration platforms is competitive and rapidly changing. Certain features of our platform compete in the cloud storage market with products offered by Amazon, Apple, Google, and Microsoft, and in the content collaboration market with products offered by Atlassian, Google, and Microsoft. We compete with Box on a more limited basis in the cloud storage market for deployments by large enterprises. We also compete with smaller private companies that offer point solutions in the cloud storage market or the content collaboration market. We believe the principal competitive factors in our markets include the following:

With the introduction of new technologies and market entrants, we expect competition to intensify in the future. Many of our actual and potential competitors benefit from competitive advantages over us, such as greater

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name recognition, longer operating histories, more varied products and services, larger marketing budgets, more established marketing relationships, access to larger user bases, major distribution agreements with hardware manufacturers and resellers, and greater financial, technical, and other resources. Some of our competitors may make acquisitions or enter into strategic relationships to offer a broader range of products and services than we do. These combinations may make it more difficult for us to compete effectively. We expect these trends to continue as competitors attempt to strengthen or maintain their market positions.

Demand for our platform is also sensitive to price. Many factors, including our marketing, user acquisition and technology costs, and our current and future competitors’ pricing and marketing strategies, can significantly affect our pricing strategies. Certain of our competitors offer, or may in the future offer, lower-priced or free products or services that compete with our platform or may bundle and offer a broader range of products and services. Similarly, certain competitors may use marketing strategies that enable them to acquire users at a lower cost than us. There can be no assurance that we will not be forced to engage in price-cutting initiatives or to increase our marketing and other expenses to attract and retain users in response to competitive pressures, either of which could materially and adversely affect our business, results of operations, and financial condition.

We may not be able to respond to rapid technological changes, extend our platform, or develop new features.

The content collaboration market is characterized by rapid technological change and frequent new product and service introductions. Our ability to grow our user base and increase revenue from existing users will depend heavily on our ability to enhance and improve our platform, introduce new features and products, and interoperate across an increasing range of devices, operating systems, and third-party applications. Users may require features and capabilities that our current platform does not have. We invest significantly in research and development, and our goal is to focus our spending on measures that improve quality and ease of adoption and create organic user demand for our platform. For example, we recently introduced Paper, a new collaborative product experience, and Smart Sync, a new advanced productivity feature, to add additional functionality to our platform. There is no assurance that our enhancements to our platform or our new product experiences, features, or capabilities will be compelling to our users or gain market acceptance. If our research and development investments do not accurately anticipate user demand, or if we fail to develop our platform in a manner that satisfies user preferences in a timely and cost-effective manner, we may fail to retain our existing users or increase demand for our platform.

The introduction of new products and services by competitors or the development of entirely new technologies to replace existing offerings could make our platform obsolete or adversely affect our business, results of operations, and financial condition. We may experience difficulties with software development, design, or marketing that could delay or prevent our development, introduction, or implementation of new product experiences, features, or capabilities. We have in the past experienced delays in our internally planned release dates of new features and capabilities, and there can be no assurance that new product experiences, features, or capabilities will be released according to schedule. Any delays could result in adverse publicity, loss of revenue or market acceptance, or claims by users brought against us, all of which could have a material and adverse effect on our reputation, business, results of operations, and financial condition. Moreover, new productivity features to our platform, such as Smart Sync, may require substantial investment, and we have no assurance that such investments will be successful. If users do not widely adopt our new product experiences, features, and capabilities, we may not be able to realize a return on our investment. If we are unable to develop, license, or acquire new features and capabilities to our platform on a timely and cost-effective basis, or if such enhancements do not achieve market acceptance, our business, results of operations, and financial condition could be adversely affected.

We may not successfully manage our growth or plan for future growth.

Since our founding in 2007, we have experienced rapid growth. For example, our headcount has grown from 1,446 employees as of December 31, 2015, to 1,858 employees as of December 31, 2017, with employees

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located both in the United States and internationally. The growth and expansion of our business places a continuous significant strain on our management, operational, and financial resources. Further growth of our operations to support our user base or our expanding third-party relationships, our information technology systems, and our internal controls and procedures may not be adequate to support our operations. In addition, as we continue to grow, we face challenges of integrating, developing, and motivating a rapidly growing employee base in various countries around the world. Certain members of our management have not previously worked together for an extended period of time and some do not have experience managing a public company, which may affect how they manage our growth. Managing our growth will also require significant expenditures and allocation of valuable management resources.

In addition, our rapid growth may make it difficult to evaluate our future prospects. Our ability to forecast our future results of operations is subject to a number of uncertainties, including our ability to effectively plan for and model future growth. We have encountered in the past, and may encounter in the future, risks and uncertainties frequently experienced by growing companies in rapidly changing industries. If we fail to achieve the necessary level of efficiency in our organization as it grows, or if we are not able to accurately forecast future growth, our business, results of operations, and financial condition could be harmed.

Our lack of a significant outbound sales force may limit the potential growth of our business.

Historically, our business model has been driven by organic adoption and viral growth, with more than 90% of our revenue generated from self-serve channels. As a result, we do not have a significant outbound sales force, which has enabled us to be more efficient with our sales and marketing spend. Although we believe our business model can continue to scale without a large outbound sales force, our word-of-mouth and user referral marketing model may not continue to be as successful as we anticipate, and our limited experience selling directly to large organizations through our outbound sales force may impede our future growth. As we continue to scale our business, an enhanced sales infrastructure could assist in reaching larger organizations and growing our revenue. Identifying and recruiting additional qualified sales personnel and training them would require significant time, expense, and attention, and would significantly impact our business model. Further, adding more sales personnel would change our cost structure and results of operations, and we may have to reduce other expenses in order to accommodate a corresponding increase in sales and marketing expenses. If our limited experience selling and marketing to large organizations prevents us from reaching larger organizations and growing our revenue, and if we are unable to hire, develop, and retain talented sales personnel in the future, our business, results of operations, and financial condition could be adversely affected.

We may expand sales to large organizations, which could lengthen sales cycles and result in greater deployment challenges.

As our business evolves, we may need to invest more resources into sales to large organizations. Large organizations may undertake a significant evaluation and negotiation process, which can lengthen our sales cycle. We may also face unexpected deployment challenges with large organizations or more complicated deployment of our platform. Large organizations may demand more configuration and integration of our platform or require additional security management or control features. We may spend substantial time, effort, and money on sales efforts to large organizations without any assurance that our efforts will produce any sales. As a result, sales to large organizations may lead to greater unpredictability in our business, results of operations, and financial condition.

Any failure to offer high-quality customer support may harm our relationships with our users and our financial results.

We have designed our platform to be easy to adopt and use with minimal to no support necessary. Any increased user demand for customer support could increase costs and harm our results of operations. In addition, as we continue to grow our operations and support our global user base, we need to be able to continue to provide

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efficient customer support that meets our customers’ needs globally at scale. Paying users receive additional customer support features and the number of our paying users has grown significantly, which will put additional pressure on our support organization. For example, the number of paying users has grown from 6.5 million as of December 31, 2015, to 11 million as of December 31, 2017. If we are unable to provide efficient customer support globally at scale, our ability to grow our operations may be harmed and we may need to hire additional support personnel, which could harm our results of operations. Our new user signups are highly dependent on our business reputation and on positive recommendations from our existing users. Any failure to maintain high-quality customer support, or a market perception that we do not maintain high-quality customer support, could harm our reputation, business, results of operations, and financial condition.

Our quarterly results may fluctuate significantly and may not fully reflect the underlying performance of our business.

Our quarterly results of operations, including our revenue, gross margin, operating margin, profitability, cash flow from operations, and deferred revenue, may vary significantly in the future and period-to-period comparisons of our results of operations may not be meaningful. Accordingly, the results of any one quarter should not be relied upon as an indication of future performance. Our quarterly results of operations may fluctuate as a result of a variety of factors, many of which are outside of our control, and as a result, may not fully reflect the underlying performance of our business. Fluctuation in quarterly results may negatively impact the value of our securities. Factors that may cause fluctuations in our quarterly results of operations include, without limitation, those listed below:

Our results of operations may not immediately reflect downturns or upturns in sales because we recognize revenue from our users over the term of their subscriptions with us.

We recognize revenue from subscriptions to our platform over the terms of these subscriptions. Our subscription arrangements generally have monthly or annual contractual terms, and we also have a small percentage of multi-year contractual terms. Amounts that have been billed are initially recorded as deferred revenue until the revenue is recognized. As a result, a large portion of our revenue for each quarter reflects deferred revenue from subscriptions entered into during previous quarters, and downturns or upturns in subscription sales, or renewals and potential changes in our pricing policies may not be reflected in our results of operations until later periods. Our subscription model also makes it difficult for us to rapidly increase our revenue through additional sales in any period, as subscription revenue from new users is recognized over the

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applicable subscription term. By contrast, a significant majority of our costs are expensed as incurred, which occurs as soon as a user starts using our platform. As a result, an increase in users could result in our recognition of more costs than revenue in the earlier portion of the subscription term. We may not attain sufficient revenue to maintain positive cash flow from operations or achieve profitability in any given period.

We depend on our key personnel and other highly qualified personnel, and if we fail to attract, integrate, and retain our personnel, and maintain our unique corporate culture, our business could be harmed.

We depend on the continued service and performance of our key personnel. In particular, Andrew W. Houston, our President and Chief Executive Officer and one of our co-founders, is critical to our vision, strategic direction, culture, and offerings. Some of our other key personnel have recently joined us and are still being integrated into our company. We may continue to make changes to our management team, which could make it difficult to execute on our business plans and strategies. New hires also require significant training and, in most cases, take significant time before they achieve full productivity. Our failure to successfully integrate these key personnel into our business could adversely affect our business.

We do not have long-term employment agreements with any of our officers or key personnel. In addition, many of our key technologies and systems are custom-made for our business by our key personnel. The loss of key personnel, including key members of our management team, as well as certain of our key marketing, sales, product development, or technology personnel, could disrupt our operations and have an adverse effect on our ability to grow our business.

To execute our growth plan, we must attract and retain highly qualified personnel. Competition for these employees is intense, particularly in the San Francisco Bay Area where our headquarters are located, and we may not be successful in attracting and retaining qualified personnel. We have from time to time in the past experienced, and we expect to continue to experience, difficulty in hiring and retaining highly skilled employees with appropriate qualifications. Our recent hires and planned hires may not become as productive as we expect, and we may be unable to hire, integrate, or retain sufficient numbers of qualified individuals. Many of the companies with which we compete for experienced personnel have greater resources than we have. In addition, in making employment decisions, particularly in the internet and high-technology industries, job candidates often consider the value of the equity they are to receive in connection with their employment. Employees may be more likely to leave us if the shares they own or the shares underlying their equity incentive awards have significantly appreciated or significantly reduced in value. Many of our employees may receive significant proceeds from sales of our equity in the public markets after this offering, which may reduce their motivation to continue to work for us. If we fail to attract new personnel, or fail to retain and motivate our current personnel, our business and growth prospects could be harmed.

Additionally, if we do not maintain and continue to develop our corporate culture as we grow and evolve, it could harm our ability to foster the innovation, creativity, and teamwork we believe that we need to support our growth. Additions of executive-level management and large numbers of employees could significantly and adversely impact our culture.

Our business depends on a strong brand, and if we are not able to maintain and enhance our brand, our ability to expand our base of users will be impaired and our business, results of operations, and financial condition will be harmed.

We believe that our brand identity and awareness have contributed to our success and have helped fuel our efficient go-to-market strategy. We also believe that maintaining and enhancing the Dropbox brand is critical to expanding our base of users. We anticipate that, as our market becomes increasingly competitive, maintaining and enhancing our brand may become increasingly difficult and expensive. Any unfavorable publicity or consumer perception of our platform or the providers of content collaboration solutions generally could adversely affect our reputation and our ability to attract and retain users. Additionally, if we fail to promote and maintain

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the Dropbox brand, or if we incur excessive expenses in this effort, our business, results of operations, and financial condition will be materially and adversely affected.

We are continuing to expand our operations outside the United States, where we may be subject to increased business and economic risks that could impact our results of operations.

We have paying users across 180 countries and approximately half of our revenue in the year ended December 31, 2017 was generated from paying users outside the United States. We expect to continue to expand our international operations, which may include opening offices in new jurisdictions and providing our platform in additional languages. Any new markets or countries into which we attempt to sell subscriptions to our platform may not be receptive. For example, we may not be able to expand further in some markets if we are not able to satisfy certain government- and industry-specific requirements. In addition, our ability to manage our business and conduct our operations internationally requires considerable management attention and resources and is subject to the particular challenges of supporting a rapidly growing business in an environment of multiple languages, cultures, customs, legal and regulatory systems, alternative dispute systems, and commercial markets. International expansion has required, and will continue to require, investment of significant funds and other resources. Operating internationally subjects us to new risks and may increase risks that we currently face, including risks associated with:

Compliance with laws and regulations applicable to our global operations substantially increases our cost of doing business in international jurisdictions. We may be unable to keep current with changes in laws and regulations as they change. Although we have implemented policies and procedures designed to support compliance with these laws and regulations, there can be no assurance that we will always maintain compliance

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or that all of our employees, contractors, partners, and agents will comply. Any violations could result in enforcement actions, fines, civil and criminal penalties, damages, injunctions, or reputational harm. If we are unable comply with these laws and regulations or manage the complexity of our global operations successfully, our business, results of operations, and financial condition could be adversely affected.

Our results of operations, which are reported in U.S. dollars, could be adversely affected if currency exchange rates fluctuate substantially in the future.

We conduct our business across 180 countries around the world. As we continue to expand our international operations, we will become more exposed to the effects of fluctuations in currency exchange rates. This exposure is the result of selling in multiple currencies and operating in foreign countries where the functional currency is the local currency. In 2017, 29% of our sales were denominated in currencies other than U.S. dollars. Our expenses, by contrast, are primarily denominated in U.S. dollars. As a result, any increase in the value of the U.S. dollar against these foreign currencies could cause our revenue to decline relative to our costs, thereby decreasing our gross margins. Our results of operations are primarily subject to fluctuations in the euro and British pound sterling. Because we conduct business in currencies other than U.S. dollars, but report our results of operations in U.S. dollars, we also face remeasurement exposure to fluctuations in currency exchange rates, which could hinder our ability to predict our future results and earnings and could materially impact our results of operations. We do not currently maintain a program to hedge exposures to non-U.S. dollar currencies.

We depend on our infrastructure and third-party datacenters, and any disruption in the operation of these facilities or failure to renew the services could adversely affect our business.

We host our services and serve all of our users using a combination of our own custom-built infrastructure that we lease and operate in co-location facilities and third-party datacenter services such as Amazon Web Services. While we typically control and have access to the servers we operate in co-location facilities and the components of our custom-built infrastructure that are located in those co-location facilities, we control neither the operation of these facilities nor our third-party service providers. Furthermore, we have no physical access or control over the services provided by Amazon Web Services.

Datacenter leases and agreements with the providers of datacenter services expire at various times. The owners of these datacenters and providers of these datacenter services may have no obligation to renew their agreements with us on commercially reasonable terms, or at all. Problems faced by datacenters, with our third-party datacenter service providers, with the telecommunications network providers with whom we or they contract, or with the systems by which our telecommunications providers allocate capacity among their users, including us, could adversely affect the experience of our users. Our third-party datacenter operators could decide to close their facilities or cease providing services without adequate notice. In addition, any financial difficulties, such as bankruptcy, faced by our third-party datacenters operators or any of the service providers with whom we or they contract may have negative effects on our business, the nature and extent of which are difficult to predict.

If the datacenters and service providers that we use are unable to keep up with our growing needs for capacity, or if we are unable to renew our agreements with datacenters, and service providers on commercially reasonable terms, we may be required to transfer servers or content to new datacenters or engage new service providers, and we may incur significant costs, and possible service interruption in connection with doing so. Any changes in third-party service levels at datacenters or any real or perceived errors, defects, disruptions, or other performance problems with our platform could harm our reputation and may result in damage to, or loss or compromise of, our users’ content. Interruptions in our platform might, among other things, reduce our revenue, cause us to issue refunds to users, subject us to potential liability, harm our reputation, or decrease our renewal rates.

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We have relationships with third parties to provide, develop, and create applications that integrate with our platform, and our business could be harmed if we are not able to continue these relationships.

We use software and services licensed and procured from third parties to develop and offer our platform. We may need to obtain future licenses and services from third parties to use intellectual property and technology associated with the development of our platform, which might not be available to us on acceptable terms, or at all. Any loss of the right to use any software or services required for the development and maintenance of our platform could result in delays in the provision of our platform until equivalent technology is either developed by us, or, if available from others, is identified, obtained, and integrated, which could harm our platform and business. Any errors or defects in third-party software or services could result in errors or a failure of our platform, which could harm our business, results of operations, and financial condition.

We also depend on our ecosystem of developers to create applications that will integrate with our platform. As of December 31, 2017, Dropbox was receiving over 50 billion API calls per month, and more than 500,000 developers had registered and built applications on our platform. Our reliance on this ecosystem of developers creates certain business risks relating to the quality of the applications built using our APIs, service interruptions of our platform from these applications, lack of service support for these applications, and possession of intellectual property rights associated with these applications. We may not have the ability to control or prevent these risks. As a result, issues relating to these applications could adversely affect our business, brand, and reputation.

We are subject to a variety of U.S. and international laws that could subject us to claims, increase the cost of operations, or otherwise harm our business due to changes in the laws, changes in the interpretations of the laws, greater enforcement of the laws, or investigations into compliance with the laws.

We are subject to compliance with various laws, including those covering copyright, indecent content, child protection, consumer protection, and similar matters. There have been instances where improper or illegal content has been stored on our platform without our knowledge. As a service provider, we do not regularly monitor our platform to evaluate the legality of content stored on it. While to date we have not been subject to material legal or administrative actions as result of this content, the laws in this area are currently in a state of flux and vary widely between jurisdictions. Accordingly, it may be possible that in the future we and our competitors may be subject to legal actions, along with the users who uploaded such content. In addition, regardless of any legal liability we may face, our reputation could be harmed should there be an incident generating extensive negative publicity about the content stored on our platform. Such publicity could harm our business and results of operations.

We are also subject to consumer protection laws that may impact our sales and marketing efforts, including laws related to subscriptions, billing, and auto-renewal. These laws, as well as any changes in these laws, could adversely affect our self-serve model and make it more difficult for us to retain and upgrade paying users and attract new ones. Additionally, we have in the past, are currently, and may from time to time in the future become the subject of inquiries and other actions by regulatory authorities as a result of our business practices, including our subscription, billing, and auto-renewal policies. Consumer protection laws may be interpreted or applied by regulatory authorities in a manner that could require us to make changes to our operations or incur fines, penalties or settlement expenses, which may result in harm to our business, results of operations, and brand.

Our platform depends on the ability of our users to access the internet and our platform has been blocked or restricted in some countries for various reasons. For example, our platform is blocked in the People’s Republic of China. If we fail to anticipate developments in the law, or fail for any reason to comply with relevant law, our platform could be further blocked or restricted and we could be exposed to significant liability that could harm our business.

We are also subject to various U.S. and international anti-corruption laws, such as the U.S. Foreign Corrupt Practices Act and the U.K. Bribery Act, as well as other similar anti-bribery and anti-kickback laws and

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regulations. These laws and regulations generally prohibit companies and their employees and intermediaries from authorizing, offering, or providing improper payments or benefits to officials and other recipients for improper purposes. Although we take precautions to prevent violations of these laws, our exposure for violating these laws increases as we continue to expand our international presence and any failure to comply with such laws could harm our reputation and our business.

We are subject to export and import control laws and regulations that could impair our ability to compete in international markets or subject us to liability if we violate such laws and regulations.

We are subject to U.S. export controls and sanctions regulations that prohibit the shipment or provision of certain products and services to certain countries, governments, and persons targeted by U.S. sanctions. While we take precautions to prevent our products and services from being exported in violation of these laws, including implementing IP address blocking, we cannot guarantee that the precautions we take will prevent violations of export control and sanctions laws. For example, in 2011, we provided certain downloadable portions of our software to international users that, prior to export, required either a one-time product review or application for an encryption registration number in lieu of such product review. These exports were likely made in violation of U.S. export control and sanction laws. In March 2011, we filed a Final Voluntary Self Disclosure with the U.S. Department of Commerce’s Bureau of Industry and Security, or BIS, concerning these potential violations. In June 2012, BIS notified us that it had completed its review of these matters and closed its review with the issuance of a Warning Letter. No monetary penalties were assessed against us by BIS with respect to the 2011 filing. In addition, in 2017, we discovered that our platform has been accessed by certain users in apparent violation of United States sanctions regulations. We filed an Initial Voluntary Self Disclosure in October 2017 with the Office of Foreign Assets Control, or OFAC, and a Final Voluntary Self Disclosure with OFAC in February 2018. If we are found to be in violation of U.S. sanctions or export control laws, it could result in substantial fines and penalties for us and for the individuals working for us.

In addition, various countries regulate the import and export of certain encryption and other technology, including import and export permitting and licensing requirements, and have enacted laws that could limit our ability to distribute our products or could limit our users’ ability to access our platform in those countries. Changes in our platform or client-side software, or future changes in export and import regulations may prevent our users with international operations from deploying our platform globally or, in some cases, prevent the export or import of our platform to certain countries, governments, or persons altogether. Any change in export or import regulations, economic sanctions or related legislation, or change in the countries, governments, persons or technologies targeted by such regulations, could result in decreased use of our platform by, or in our decreased ability to export or sell subscriptions to our platform to, existing or potential users with international operations. Any decreased use of our platform or limitation on our ability to export or sell our products would likely adversely affect our business, results of operations, and financial results.

Our actual or perceived failure to comply with privacy, data protection, and information security laws, regulations, and obligations could harm our business.

We receive, store, process, and use personal information and other user content. There are numerous federal, state, local, and international laws and regulations regarding privacy, data protection, information security, and the storing, sharing, use, processing, transfer, disclosure, and protection of personal information and other content, the scope of which are changing, subject to differing interpretations, and may be inconsistent among countries, or conflict with other rules. We are also subject to the terms of our privacy policies and obligations to third parties related to privacy, data protection, and information security. We strive to comply with applicable laws, regulations, policies, and other legal obligations relating to privacy, data protection, and information security to the extent possible. However, the regulatory framework for privacy and data protection worldwide is, and is likely to remain, uncertain for the foreseeable future, and it is possible that these or other actual or alleged obligations may be interpreted and applied in a manner that is inconsistent from one jurisdiction to another and may conflict with other rules or our practices.

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We also expect that there will continue to be new laws, regulations, and industry standards concerning privacy, data protection, and information security proposed and enacted in various jurisdictions. For example, European legislators have adopted a General Data Protection Regulation, or GDPR, that will, when effective in May 2018, supersede current European Union, or EU, data protection legislation, impose more stringent EU data protection requirements, and provide for greater penalties for noncompliance. Further, following a referendum in June 2016 in which voters in the United Kingdom approved an exit from the EU, the United Kingdom government has initiated a process to leave the EU, or Brexit. Brexit has created uncertainty with regard to the regulation of data protection in the United Kingdom. In particular, it is unclear whether the United Kingdom will enact data protection laws or regulations designed to be consistent with the pending EU General Data Protection Regulation and how data transfers to and from the United Kingdom will be regulated. Additionally, although we have self-certified under the U.S.-EU and U.S.-Swiss Privacy Shield Frameworks with regard to our transfer of certain personal data from the EU and Switzerland to the United States, some regulatory uncertainty remains surrounding the future of data transfers from the EU and Switzerland to the United States, and we are closely monitoring regulatory developments in this area.

Any failure or perceived failure by us to comply with our privacy policies, our privacy-related obligations to users or other third parties, or any of our other legal obligations relating to privacy, data protection, or information security may result in governmental investigations or enforcement actions, litigation, claims, or public statements against us by consumer advocacy groups or others and could result in significant liability or cause our users to lose trust in us, which could have an adverse effect on our reputation and business. Furthermore, the costs of compliance with, and other burdens imposed by, the laws, regulations, and policies that are applicable to the businesses of our users may limit the adoption and use of, and reduce the overall demand for, our services.

Additionally, if third parties we work with, such as vendors or developers, violate applicable laws or regulations or our policies, such violations may also put our users’ content at risk and could in turn have an adverse effect on our business. Any significant change to applicable laws, regulations, or industry practices regarding the collection, use, retention, security, or disclosure of our users’ content, or regarding the manner in which the express or implied consent of users for the collection, use, retention, or disclosure of such content is obtained, could increase our costs and require us to modify our services and features, possibly in a material manner, which we may be unable to complete, and may limit our ability to store and process user data or develop new services and features.

Our business could be adversely impacted by changes in internet access for our users or laws specifically governing the internet.

Our platform depends on the quality of our users’ access to the internet. Certain features of our platform require significant bandwidth and fidelity to work effectively. Internet access is frequently provided by companies that have significant market power that could take actions that degrade, disrupt or increase the cost of user access to our platform, which would negatively impact our business. We could incur greater operating expenses and our user acquisition and retention could be negatively impacted if network operators:

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On December 14, 2017, the Federal Communications Commission voted to repeal the “net neutrality” rules and return to a “light-touch” regulatory framework. However, the repeal has not yet taken effect and a number of parties have already stated their intent to appeal this order; thus, the future impact of such repeal and any challenge thereto remains uncertain. The rules were designed to ensure that all online content is treated the same by internet service providers and other companies that provide broadband services. Should the repeal of net neutrality rules take effect, we could incur greater operating expenses, which could harm our results of operations.

As the internet continues to experience growth in the number of users, frequency of use, and amount of data transmitted, the internet infrastructure that we and our users rely on may be unable to support the demands placed upon it. The failure of the internet infrastructure that we or our users rely on, even for a short period of time, could undermine our operations and harm our results of operations.

In addition, there are various laws and regulations that could impede the growth of the internet or other online services, and new laws and regulations may be adopted in the future. These laws and regulations could, in addition to limiting internet neutrality, involve taxation, tariffs, privacy, data protection, content, copyrights, distribution, electronic contracts and other communications, consumer protection, and the characteristics and quality of services, any of which could decrease the demand for, or the usage of, our platform. Legislators and regulators may make legal and regulatory changes, or interpret and apply existing laws, in ways that require us to incur substantial costs, expose us to unanticipated civil or criminal liability, or cause us to change our business practices. These changes or increased costs could materially harm our business, results of operations, and financial condition.

We are currently, and may be in the future, party to intellectual property rights claims and other litigation matters and, if resolved adversely, they could have a significant impact on our business, results of operations, or financial condition.

We own a large number of patents, copyrights, trademarks, domain names, and trade secrets and, from time to time, are subject to litigation based on allegations of infringement, misappropriation or other violations of intellectual property, or other rights. As we face increasing competition and gain an increasingly high profile, the possibility of intellectual property rights claims, commercial claims, and other assertions against us grows. We have in the past been, are currently, and may from time to time in the future become, a party to litigation and disputes related to our intellectual property, our business practices, and our platform. The costs of supporting litigation and dispute resolution proceedings are considerable, and there can be no assurances that a favorable outcome will be obtained. We may need to settle litigation and disputes on terms that are unfavorable to us, or we may be subject to an unfavorable judgment that may not be reversible upon appeal. The terms of any settlement or judgment may require us to cease some or all of our operations or pay substantial amounts to the other party. With respect to any intellectual property rights claim, we may have to seek a license to continue practices found to be in violation of third-party rights, which may not be available on reasonable terms and may significantly increase our operating expenses. A license to continue such practices may not be available to us at all, and we may be required to develop alternative non-infringing technology or practices or discontinue the practices. The development of alternative, non-infringing technology or practices could require significant effort and expense. Our business, results of operations, and financial condition could be materially and adversely affected as a result.

Our failure to protect our intellectual property rights and proprietary information could diminish our brand and other intangible assets.

We rely and expect to continue to rely on a combination of patent, patent licenses, trade secret, and domain name protection, trademark, and copyright laws, as well as confidentiality and license agreements with our employees, consultants, and third parties, to protect our intellectual property and proprietary rights. In the United States and abroad, we have over 600 issued patents and more than 600 pending patent applications. However, third parties may knowingly or unknowingly infringe our proprietary rights, third parties may challenge our

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proprietary rights, pending and future patent, trademark, and copyright applications may not be approved, and we may not be able to prevent infringement without incurring substantial expense. We have also devoted substantial resources to the development of our proprietary technologies and related processes. In order to protect our proprietary technologies and processes, we rely in part on trade secret laws and confidentiality agreements with our employees, consultants, and third parties. These agreements may not effectively prevent disclosure of confidential information and may not provide an adequate remedy in the event of unauthorized disclosure of confidential information. In addition, others may independently discover our trade secrets, in which case we would not be able to assert trade secret rights, or develop similar technologies and processes. Further, laws in certain jurisdictions may afford little or no trade secret protection, and any changes in, or unexpected interpretations of, the intellectual property laws in any country in which we operate may compromise our ability to enforce our intellectual property rights. Costly and time-consuming litigation could be necessary to enforce and determine the scope of our proprietary rights. If the protection of our proprietary rights is inadequate to prevent use or appropriation by third parties, the value of our platform, brand, and other intangible assets may be diminished and competitors may be able to more effectively replicate our platform and its features. Any of these events could materially and adversely affect our business, results of operations, and financial condition.

Our use of open source software could negatively affect our ability to offer and sell subscriptions to our platform and subject us to possible litigation.

A portion of the technologies we use incorporates open source software, and we may incorporate open source software in the future. Open source software is generally licensed by its authors or other third parties under open source licenses. These licenses may subject us to certain unfavorable conditions, including requirements that we offer our platform that incorporates the open source software for no cost, that we make publicly available source code for modifications or derivative works we create based upon, incorporating or using the open source software, and/or that we license such modifications or derivative works under the terms of the particular open source license. Additionally, if a third-party software provider has incorporated open source software into software that we license from such provider, we could be required to disclose any of our source code that incorporates or is a modification of our licensed software. If an author or other third party that distributes open source software that we use or license were to allege that we had not complied with the conditions of the applicable license, we could be required to incur significant legal expenses defending against those allegations and could be subject to significant damages, enjoined from offering or selling our solutions that contained the open source software, and required to comply with the foregoing conditions. Any of the foregoing could disrupt and harm our business, results of operations, and financial condition.

Our ability to sell subscriptions to our platform could be harmed by real or perceived material defects or errors in our platform.

The software technology underlying our platform is inherently complex and may contain material defects or errors, particularly when first introduced or when new features or capabilities are released. We have from time to time found defects or errors in our platform, and new defects or errors in our existing platform or new software may be detected in the future by us or our users. There can be no assurance that our existing platform and new software will not contain defects. Any real or perceived errors, failures, vulnerabilities, or bugs in our platform could result in negative publicity or lead to data security, access, retention, or other performance issues, all of which could harm our business. The costs incurred in correcting such defects or errors may be substantial and could harm our results of operations and financial condition. Moreover, the harm to our reputation and legal liability related to such defects or errors may be substantial and could harm our business, results of operations, and financial condition.

We also utilize hardware purchased or leased and software and services licensed from third parties to offer our platform. Any defects in, or unavailability of, our or third-party software, services, or hardware that cause interruptions to the availability of our services, loss of data, or performance issues could, among other things:

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We may acquire other businesses or receive offers to be acquired, which could require significant management attention, disrupt our business, or dilute stockholder value.

Part of our business strategy is to make acquisitions of other companies, products, and technologies. We have limited experience in acquisitions. We may not be able to find suitable acquisition candidates and we may not be able to complete acquisitions on favorable terms, if at all. If we do complete acquisitions, we may not ultimately strengthen our competitive position or achieve our goals, and any acquisitions we complete could be viewed negatively by users, developers, or investors. In addition, we may not be able to integrate acquired businesses successfully or effectively manage the combined company following an acquisition. If we fail to successfully integrate our acquisitions, or the people or technologies associated with those acquisitions, into our company, the results of operations of the combined company could be adversely affected. Any integration process will require significant time and resources, require significant attention from management, and disrupt the ordinary functioning of our business, and we may not be able to manage the process successfully, which could adversely affect our business, results of operations, and financial condition. In addition, we may not successfully evaluate or utilize the acquired technology and accurately forecast the financial impact of an acquisition transaction, including accounting charges.

We may have to pay cash, incur debt, or issue equity securities to pay for any such acquisition, each of which could affect our financial condition or the value of our capital stock. The sale of equity to finance any such acquisitions could result in dilution to our stockholders. If we incur more debt, it would result in increased fixed obligations and could also subject us to covenants or other restrictions that would impede our ability to flexibly operate our business.

Our business may be significantly impacted by a change in the economy, including any resulting effect on consumer or business spending.

Our business may be affected by changes in the economy generally, including any resulting effect on spending by our business and consumer users. Some of our users may view a subscription to our platform as a discretionary purchase, and our paying users may reduce their discretionary spending on our platform during an economic downturn. If an economic downturn were to occur, we may experience such a reduction in the future, especially in the event of a prolonged recessionary period. As a result, our business, results of operations, and financial condition may be significantly affected by changes in the economy generally.

Our business could be disrupted by catastrophic events.

Occurrence of any catastrophic event, including earthquake, fire, flood, tsunami, or other weather event, power loss, telecommunications failure, software or hardware malfunctions, cyber-attack, war, or terrorist attack, could result in lengthy interruptions in our service. In particular, our U.S. headquarters and some of the datacenters we utilize are located in the San Francisco Bay Area, a region known for seismic activity, and our insurance coverage may not compensate us for losses that may occur in the event of an earthquake or other significant natural disaster. In addition, acts of terrorism could cause disruptions to the internet or the economy as a whole. Even with our disaster recovery arrangements, our service could be interrupted. If our systems were to fail or be negatively impacted as a result of a natural disaster or other event, our ability to deliver products to our

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users would be impaired or we could lose critical data. If we are unable to develop adequate plans to ensure that our business functions continue to operate during and after a disaster, and successfully execute on those plans in the event of a disaster or emergency, our business, results of operations, financial condition, and reputation would be harmed.

We may have exposure to greater than anticipated tax liabilities, which could adversely impact our results of operations.

While to date we have not incurred significant income taxes in operating our business, we are subject to income taxes in the United States and various jurisdictions outside of the United States. Our effective tax rate could fluctuate due to changes in the mix of earnings and losses in countries with differing statutory tax rates. Our tax expense could also be impacted by changes in non-deductible expenses, changes in excess tax benefits of stock-based compensation, changes in the valuation of deferred tax assets and liabilities and our ability to utilize them, the applicability of withholding taxes and effects from acquisitions.

Our tax provision could also be impacted by changes in accounting principles, changes in U.S. federal, state, or international tax laws applicable to corporate multinationals such as the recent legislation enacted in the United States, United Kingdom and Australia, other fundamental law changes currently being considered by many countries, and changes in taxing jurisdictions’ administrative interpretations, decisions, policies, and positions. Additionally, in October 2015, the Organization for Economic Co-Operation and Development released final guidance covering various topics, including transfer pricing, country-by-country reporting, and definitional changes to permanent establishment that could ultimately impact our tax liabilities.

We are subject to review and audit by U.S. federal, state, local, and foreign tax authorities. Such tax authorities may disagree with tax positions we take and if any such tax authority were to successfully challenge any such position, our financial results and operations could be materially and adversely affected. We may also be subject to additional tax liabilities due to changes in non-income based taxes resulting from changes in federal, state, or international tax laws, changes in taxing jurisdictions’ administrative interpretations, decisions, policies, and positions, results of tax examinations, settlements or judicial decisions, changes in accounting principles, changes to the business operations, including acquisitions, as well as the evaluation of new information that results in a change to a tax position taken in a prior period.

Our ability to use our net operating loss carryforwards and certain other tax attributes may be limited.

As of December 31, 2017, we had $312.2 million of federal and $143.0 million of state net operating loss carryforwards available to reduce future taxable income, which will begin to expire in 2031 for federal and 2030 for state tax purposes. As of December 31, 2017, we also had $289.3 million of foreign net operating loss carryforwards available to reduce future taxable income, which will carryforward indefinitely. In addition, we had $22.9 million of foreign acquired net operating losses, which will carryforward indefinitely. It is possible that we will not generate taxable income in time to use these net operating loss carryforwards before their expiration or at all. Under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, if a corporation undergoes an “ownership change,” the corporation’s ability to use its pre-change net operating loss carryforwards and other pre-change attributes, such as research tax credits, to offset its post-change income may be limited. In general, an “ownership change” will occur if there is a cumulative change in our ownership by “5-percent shareholders” that exceeds 50 percentage points over a rolling three-year period. Similar rules may apply under state tax laws. We performed a study for the period through December 31, 2017, and determined that no ownership changes exceeding 50 percentage points had occurred. Our ability to use net operating loss and tax credit carryforwards to reduce future taxable income and liabilities may be subject to annual limitations as a result of ownership changes from January 1, 2018, and subsequent years or as a result of this offering.

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Our operating results may be harmed if we are required to collect sales or other related taxes for our subscription services in jurisdictions where we have not historically done so.

We collect sales and value-added tax as part of our subscription agreements in a number of jurisdictions. One or more states or countries may seek to impose incremental or new sales, use, or other tax collection obligations on us, including for past sales by us or our resellers and other partners. A successful assertion by a state, country, or other jurisdiction that we should have been or should be collecting additional sales, use, or other taxes on our services could, among other things, result in substantial tax liabilities for past sales, create significant administrative burdens for us, discourage users from purchasing our platform, or otherwise harm our business, results of operations, and financial condition.

Our results of operations and financial condition could be materially affected by the enactment of legislation implementing changes in the U.S. or foreign taxation of international business activities or the adoption of other tax reform policies.

On December 22, 2017, the legislation commonly referred to as the Tax Cuts and Jobs Act, or the Tax Reform Act, was enacted, which contains significant changes to U.S. tax law, including, but not limited to, a reduction in the corporate tax rate and a transition to a new territorial system of taxation. The primary impact of the new legislation on our provision for income taxes was a reduction of the future tax benefits of our deferred tax assets as a result of the reduction in the corporate tax rate. However, since we have recorded a full valuation allowance against our deferred tax assets, we do not currently anticipate that these changes will have a material impact on our consolidated financial statements. The impact of the Tax Reform Act will likely be subject to ongoing technical guidance and accounting interpretation, which we will continue to monitor and assess. Provisional accounting impacts may change in future reporting periods until the accounting analysis is finalized, which will occur no later than one year from the date the Tax Reform Act was enacted. As we expand the scale of our international business activities, any changes in the U.S. or foreign taxation of such activities may increase our worldwide effective tax rate and harm our business, results of operations, and financial condition.

If we fail to maintain an effective system of disclosure controls and internal control over financial reporting, our ability to produce timely and accurate financial statements or comply with applicable regulations could be impaired.

As a public company, we will be subject to the reporting requirements of the Securities Exchange Act of 1934, as amended, or the Exchange Act, the Sarbanes-Oxley Act of 2002, or the Sarbanes-Oxley Act, and the rules and regulations of the applicable listing standards of the Nasdaq Global Select Market, or Nasdaq. We expect that the requirements of these rules and regulations will continue to increase our legal, accounting, and financial compliance costs, make some activities more difficult, time-consuming and costly, and place significant strain on our personnel, systems, and resources.

The Sarbanes-Oxley Act requires, among other things, that we maintain effective disclosure controls and procedures and internal control over financial reporting. We are continuing to develop and refine our disclosure controls and other procedures that are designed to ensure that information required to be disclosed by us in the reports that we will file with the SEC is recorded, processed, summarized, and reported within the time periods specified in SEC rules and forms and that information required to be disclosed in reports under the Exchange Act is accumulated and communicated to our principal executive and financial officers. We are also continuing to improve our internal control over financial reporting. In order to maintain and improve the effectiveness of our disclosure controls and procedures and internal control over financial reporting, we have expended, and anticipate that we will continue to expend, significant resources, including accounting-related costs and significant management oversight.

Our current controls and any new controls that we develop may become inadequate because of changes in conditions in our business. Further, weaknesses in our disclosure controls and internal control over financial

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reporting may be discovered in the future. Any failure to develop or maintain effective controls or any difficulties encountered in their implementation or improvement could harm our results of operations or cause us to fail to meet our reporting obligations and may result in a restatement of our financial statements for prior periods. Any failure to implement and maintain effective internal control over financial reporting also could adversely affect the results of periodic management evaluations and annual independent registered public accounting firm attestation reports regarding the effectiveness of our internal control over financial reporting that we will eventually be required to include in our periodic reports that will be filed with the SEC. Ineffective disclosure controls and procedures and internal control over financial reporting could also cause investors to lose confidence in our reported financial and other information, which would likely have a negative effect on the trading price of our Class A common stock. In addition, if we are unable to continue to meet these requirements, we may not be able to remain listed on Nasdaq. We are not currently required to comply with the SEC rules that implement Section 404 of the Sarbanes-Oxley Act and are therefore not required to make a formal assessment of the effectiveness of our internal control over financial reporting for that purpose. As a public company, we will be required to provide an annual management report on the effectiveness of our internal control over financial reporting commencing with our second annual report on Form 10-K.

Our independent registered public accounting firm is not required to formally attest to the effectiveness of our internal control over financial reporting until our first annual report filed with the SEC where we are an “accelerated filer” or a “large accelerated filer”. At such time, our independent registered public accounting firm may issue a report that is adverse in the event it is not satisfied with the level at which our internal control over financial reporting is documented, designed, or operating. Any failure to maintain effective disclosure controls and internal control over financial reporting could materially and adversely affect our business, results of operations, and financial condition and could cause a decline in the trading price of our Class A common stock.

Although we ceased to be an “emerging growth company,” we can continue to take advantage of certain reduced disclosure requirements in this registration statement, which may make our Class A common stock less attractive to investors.

We ceased to be an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act of 2012, or the JOBS Act, on December 31, 2017. However, because we ceased to be an “emerging growth company” after we confidentially submitted our registration statement related to this offering to the SEC, we will continue to be treated as an “emerging growth company” for certain purposes until the earlier of the date on which we complete this offering or December 31, 2018. As such, we have taken advantage of certain reduced disclosure obligations regarding selected financial data and executive compensation arrangements in our registration statement related to this offering that are not available to non-emerging growth companies. We cannot predict if investors will find our Class A common stock less attractive because we have relied on these exemptions. If some investors find our Class A common stock less attractive as a result, there may be less demand for our Class A common stock and the price that some investors are willing to pay for our Class A common stock may decrease.

Our reported results of operations may be adversely affected by changes in accounting principles generally accepted in the United States.

Generally accepted accounting principles in the United States are subject to interpretation by the Financial Accounting Standards Board, or FASB, the SEC, and various bodies formed to promulgate and interpret appropriate accounting principles. A change in these principles or interpretations could have a significant effect on our reported results of operations, and may even affect the reporting of transactions completed before the announcement or effectiveness of a change. For example, in May 2014, the FASB issued Accounting Standards Update, or ASU, No. 2014-09, Revenue from Contracts with Customers (Topic 606), or Topic 606, which superseded nearly all existing revenue recognition guidance. We adopted the requirements of Topic 606 as of January 1, 2017, utilizing the full retrospective method of transition. As such, Topic 606 is reflected in our financial results for all periods presented in this prospectus. The adoption of Topic 606 primarily resulted in

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changes to our accounting policies for revenue recognition and deferred commissions, which we believe to be critical accounting policies. While the impact of adopting Topic 606 on our revenue was not material, it is difficult to predict the impact of future changes to accounting principles or our accounting policies, any of which could negatively affect our results of operations.

We recently implemented a new enterprise resource planning system, and if this new system proves ineffective or if we experience issues with the transition, we may be unable to timely or accurately prepare financial reports, make payments to our suppliers and employees, or invoice and collect from our users.

In 2017, we implemented a new enterprise resource planning, or ERP, system, including our systems for tracking revenue recognition. Our ERP system is critical to our ability to accurately maintain books and records and to prepare our financial statements. The transition to our new ERP system may be disruptive to our business if the ERP system does not work as planned or if we experience issues relating to the implementation. Such disruptions could impact our ability to timely or accurately make payments to our suppliers and employees, and could also inhibit our ability to invoice, and collect from our users. Data integrity problems or other issues may be discovered which, if not corrected, could impact our business or financial results. In addition, we may experience periodic or prolonged disruption of our financial functions arising out of this conversion, general use of such system, other periodic upgrades or updates, or other external factors that are outside of our control. If we encounter unforeseen problems with our ERP system or other related systems and infrastructure, our business, results of operations, and financial condition could be adversely affected.

Certain of our market opportunity estimates, growth forecasts, and key metrics included in this prospectus could prove to be inaccurate, and any real or perceived inaccuracies may harm our reputation and negatively affect our business.

Market opportunity estimates and growth forecasts are subject to significant uncertainty and are based on assumptions and estimates that may not prove to be accurate. The estimates and forecasts in this prospectus relating to the size and expected growth of our target market may prove to be inaccurate. Even if the markets in which we compete meet the size estimates and growth forecasted in this prospectus, our business could fail to grow at similar rates, if at all. We also rely on assumptions and estimates to calculate certain of our key metrics, such as paying users, average revenue per paying user, and free cash flow. We regularly review and may adjust our processes for calculating our key metrics to improve their accuracy. Our key metrics may differ from estimates published by third parties or from similarly titled metrics of our competitors due to differences in methodology. We have found that aggregate user activity metrics are not leading indicators of revenue or conversion. For that reason, we do not comprehensively track user activity across the Dropbox platform for financial planning and forecasting purposes. If investors or analysts do not perceive our metrics to be accurate representations of our business, or if we discover material inaccuracies in our metrics, our reputation, business, results of operations, and financial condition would be harmed.

Our revolving credit facility provides our lenders with a first-priority lien against substantially all of our intellectual property and certain other assets, and contains financial covenants and other restrictions on our actions that may limit our operational flexibility or otherwise adversely affect our results of operations.

We are party to a revolving credit and guarantee agreement, as amended, which contains a number of covenants that limit our ability and our subsidiaries’ ability to, among other things, incur additional indebtedness, pay dividends, make redemptions and repurchases of stock, make investments, loans and acquisitions, create liens, engage in transactions with affiliates, merge or consolidate with other companies, or sell substantially all of our assets. We are also required to maintain certain financial covenants, including a maximum consolidated leverage ratio and a minimum liquidity balance. The terms of our revolving credit facility may restrict our current and future operations and could adversely affect our ability to finance our future operations or capital needs or to execute preferred business strategies. In addition, complying with these covenants may make it more difficult for us to successfully execute our business strategy and compete against companies who are not subject to such restrictions.

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A failure by us to comply with the covenants or payment requirements specified in our credit agreement, as amended, could result in an event of default under the agreement, which would give the lenders the right to terminate their commitments to provide additional loans under our revolving credit facility and to declare all borrowings outstanding, together with accrued and unpaid interest and fees, to be immediately due and payable. In addition, the lenders would have the right to proceed against the collateral we granted to them, which consists of substantially all our intellectual property and certain other assets. If the debt under our revolving credit facility were to be accelerated, we may not have sufficient cash or be able to borrow sufficient funds to refinance the debt or sell sufficient assets to repay the debt, which could immediately materially and adversely affect our business, cash flows, results of operations, and financial condition. Even if we were able to obtain new financing, it may not be on commercially reasonable terms or on terms that are acceptable to us.

Our operations may be interrupted and our business, results of operations, and financial condition could be adversely affected if we default on our leasing or credit obligations.

We finance a significant portion of our expenditures through leasing arrangements, some of which are not required to be reflected on our balance sheet, and we may enter into additional similar arrangements in the future. As of December 31, 2017, we had an aggregate of $1,687.0 million of commitments to settle contractual obligations. In particular, we have used these types of arrangements to finance some of our equipment and datacenters. In addition, we may draw upon our revolving credit facility to finance our operations or for other corporate purposes, such as funding our tax withholding and remittance obligations in connection with the settlement of restricted stock units, or RSUs. If we default on these leasing or credit obligations, our leasing partners and lenders may, among other things:

In October 2017, we entered into a new lease agreement to rent office space in San Francisco, California, to serve as our new corporate headquarters. The total minimum obligations under this lease agreement are expected to be approximately $827.0 million. Before moving to our new corporate headquarters, we will continue to operate in our current corporate headquarters, during which time we will be incurring rent expense on both our current and new corporate headquarters. After moving to our new corporate headquarters, we plan to vacate our current corporate headquarters with the intention of subleasing the space to a third-party for the remainder of the lease term, which terminates in the third quarter of 2027. If we are unable to find sublessors for all or a portion of our current corporate headquarters, our results of operations will be adversely impacted as a result of this additional rent expense through 2027.

If some or all of these events were to occur, our operations may be interrupted and our ability to fund our operations or obligations, as well as our business, results of operations, and financial condition, could be adversely affected.

We may need additional capital, and we cannot be certain that additional financing will be available on favorable terms, or at all.

Historically, we have funded our operations and capital expenditures primarily through equity issuances, cash generated from our operations, and debt financing for capital purchases. Although we currently anticipate

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that our existing cash and cash equivalents, amounts available under our existing credit facilities, and cash flow from operations will be sufficient to meet our cash needs for the foreseeable future, we may require additional financing. We evaluate financing opportunities from time to time, and our ability to obtain financing will depend, among other things, on our development efforts, business plans, operating performance, and condition of the capital markets at the time we seek financing. We cannot assure you that additional financing will be available to us on favorable terms when required, or at all. If we raise additional funds through the issuance of equity or equity-linked or debt securities, those securities may have rights, preferences or privileges senior to the rights of our Class A common stock, and our stockholders may experience dilution.

Risks Related to Ownership of Our Class A Common Stock

An active trading market for our Class A common stock may never develop or be sustained.

We have been approved to list our Class A common stock on Nasdaq under the symbol “DBX”. However, we cannot assure you that an active trading market for our Class A common stock will develop on that exchange or elsewhere or, if developed, that any market will be sustained. Accordingly, we cannot assure you of the likelihood that an active trading market for our Class A common stock will develop or be maintained, the liquidity of any trading market, your ability to sell your shares of our Class A common stock when desired or the prices that you may obtain for your shares.

The trading price of our Class A common stock may be volatile, and you could lose all or part of your investment.

Prior to this offering, there has been no public market for shares of our Class A common stock. The initial public offering price of our Class A common stock was determined through negotiation among us, the selling stockholders, and the underwriters. This price does not necessarily reflect the price at which investors in the market will be willing to buy and sell shares of our Class A common stock following this offering. In addition, the trading price of our Class A common stock following this offering is likely to be volatile and could be subject to fluctuations in response to various factors, some of which are beyond our control. These fluctuations could cause you to lose all or part of your investment in our Class A common stock since you might be unable to sell your shares at or above the price you paid in this offering. Factors that could cause fluctuations in the trading price of our Class A common stock include the following:

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In addition, in the past, following periods of volatility in the overall market and the market price of a particular company’s securities, securities class action litigation has often been instituted against these companies. This litigation, if instituted against us, could result in substantial costs and a diversion of our management’s attention and resources.

The multi-class structure of our common stock will have the effect of concentrating voting control with those stockholders who held our capital stock prior to the completion of this offering and the concurrent private placement, and it may depress the trading price of our Class A common stock.

Our Class A common stock, which is the stock we are offering in this offering and the concurrent private placement, has one vote per share, our Class B common stock has ten votes per share, and our Class C common stock has no voting rights, except as otherwise required by law. Following this offering and the concurrent private placement, our directors, executive officers and holders of more than 5% of our common stock, and their respective affiliates, will hold in the aggregate 75.7% of the voting power of our capital stock (including the Co-Founder Grants and the Co-Founder Voting Agreements). We are including the Co-Founder Grants in this calculation since they are legally issued and outstanding shares of our Class A common stock and our co-founders are able to vote these shares immediately upon grant and prior to their vesting. Because of the ten-to-one voting ratio between our Class B and Class A common stock, the holders of our Class B common stock collectively will continue to control a majority of the combined voting power of our common stock and therefore be able to control all matters submitted to our stockholders for approval so long as the shares of Class B common stock represent at least 9.1% of all outstanding shares of our Class A and Class B common stock. This concentrated control will limit or preclude your ability to influence corporate matters for the foreseeable future, including the election of directors, amendments of our organizational documents and any merger, consolidation, sale of all or substantially all of our assets, or other major corporate transaction requiring stockholder approval. In addition, this may prevent or discourage unsolicited acquisition proposals or offers for our capital stock that you may feel are in your best interest as one of our stockholders.

Future transfers or sales by holders of Class B common stock will generally result in those shares converting to Class A common stock, except for certain transfers described in our amended and restated certificate of incorporation, including transfers effected for estate planning purposes where sole dispositive power and exclusive voting control with respect to the shares of Class B common stock is retained by the transferring holder and transfers between our co-founders. In addition, each outstanding share of Class B common stock held by a stockholder who is a natural person, or held by the permitted entities or permitted transferees of such stockholder (as described in our amended and restated certificate of incorporation), will convert automatically into one share of Class A common stock upon the death of such natural person. In the event of the death or permanent and total

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disability of a co-founder, shares of Class B common stock held by such co-founder, his permitted entities or permitted transferees will convert to Class A common stock, provided that the conversion will be deferred for nine months, or up to 18 months if approved by a majority of our independent directors, following his death or permanent and total disability. Transfers between our co-founders are permitted transfers and will not result in conversion of the shares of Class B common stock that are transferred; however, upon the death or total and permanent disability of the transferring co-founder, the transferred shares would convert to Class A common stock following the deferral period of nine months, or up to 18 months if approved by a majority of our independent directors. See the section titled “Description of Capital Stock – Conversion of Class B Common Stock” for additional information about conversions. The conversion of Class B common stock to Class A common stock will have the effect, over time, of increasing the relative voting power of those individual holders of Class B common stock who retain their shares in the long term.

In addition, because our Class C common stock carries no voting rights (except as otherwise required by law), if we issue Class C common stock in the future, the holders of Class B common stock may be able to elect all of our directors and to determine the outcome of most matters submitted to a vote of our stockholders for a longer period of time than would be the case if we issued Class A common stock rather than Class C common stock in such transactions. See the section titled “Description of Capital Stock—Anti-Takeover Provisions” for additional information.

In addition, in July 2017, FTSE Russell and Standard & Poor’s announced that they would cease to allow most newly public companies utilizing dual or multi-class capital structures to be included in their indices. Affected indices include the Russell 2000 and the S&P 500, S&P MidCap 400, and S&P SmallCap 600, which together make up the S&P Composite 1500. Under the announced policies, our multi-class capital structure would make us ineligible for inclusion in any of these indices, and as a result, mutual funds, exchange-traded funds, and other investment vehicles that attempt to passively track these indices will not be investing in our stock. These policies are very new and it is as of yet unclear what effect, if any, they will have on the valuations of publicly traded companies excluded from the indices, but it is possible that they may depress these valuations compared to those of other similar companies that are included.

Because of the relatively small number of shares of our Class A common stock outstanding immediately after this offering and the number of shares of Class A common stock held by our founders as a result of their RSAs, which shares have full voting rights, our co-founders will have significant influence over any vote of the Class A common stock voting as a separate class.

Based on 26,550,581 shares of Class A common stock (including the Capital Stock Conversions) outstanding as of December 31, 2017, inclusive of 14,733,333 shares of Class A common stock subject to RSAs that were granted pursuant to our Co-Founder Grants, following this offering, we will have 67,312,486 shares of Class A common stock legally issued and outstanding. As a result, until the public float of our Class A common stock increases, which is expected to occur primarily as a result of conversion of shares of Class B common stock into shares of Class A common stock upon transfer, our co-founders will hold a significant percentage of the outstanding Class A common stock. Although the terms of our amended and restated certificate of incorporation only provide for a separate vote of the holders of the Class A common stock on matters occurring after the conversion of the Class B common stock as a class, under Delaware law, certain actions may require the approval of the holders of the Class A common stock voting as a separate class. For example, if we amend our amended and restated certificate of incorporation to adversely affect our Class A common stock, Delaware law could require approval of the holders of our Class A common stock voting separately as a single class. For any vote of the Class A common stock voting as a separate class, our co-founders will heavily influence such vote until the number of outstanding shares of Class A common stock significantly increases. Further, our co-founders will have the right to vote those shares until the termination of the award even if the performance targets have not been met or are not expected to be met. To the extent that the RSAs vest, our co-founders will have the ability to gain liquidity by selling shares of our Class A common stock without reducing their voting power by converting their Class B common stock.

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A substantial portion of the outstanding shares of our Class A common stock and Class B common stock after this offering and the concurrent private placement will be restricted from immediate resale, but may be sold on a stock exchange in the near future. The large number of shares of our capital stock eligible for public sale or subject to rights requiring us to register them for public sale could depress the market price of our Class A common stock.

The market price of our Class A common stock could decline as a result of sales of a large number of shares of our Class A common stock in the market after this offering and the concurrent private placement, and the perception that these sales could occur may also depress the market price of our Class A common stock. Based on 11,817,248 shares of our Class A common stock (including the Capital Stock Conversions) and 348,501,449 shares of our Class B common stock (including the Capital Stock Conversions and the RSU Settlement) outstanding as of December 31, 2017, we will have 52,579,153 shares of our Class A common stock and 339,323,858 shares Class B common stock outstanding after this offering and the concurrent private placement. Our executive officers, directors, and the holders of substantially all of our capital stock and securities convertible into or exchangeable for our capital stock have entered into market standoff agreements with us or have entered into lock-up agreements with the underwriters under which they have agreed, subject to specific exceptions, not to sell any of our stock for 180 days following the date of this prospectus. We refer to such period as the lock-up period. Pursuant to the lock-up agreements with the underwriters, if (i) at least 120 days have elapsed since the date of this prospectus, (ii) we have publicly released our earnings results for the quarterly period during which this offering occurred, and (iii) such lock-up period is scheduled to end during or within five trading days prior to a broadly applicable period during which trading in our securities would not be permitted under our insider trading policy, or a blackout period, such lock-up period will end ten trading days prior to the commencement of such blackout period. We and the underwriters may release certain stockholders from the market standoff agreements or lock-up agreements prior to the end of the lock-up period.

As a result of these agreements and the provisions of our investors’ rights agreement described further in the section titled “Description of Capital Stock—Registration Rights,” and subject to the provisions of Rule 144 or Rule 701, shares of our Class A common stock and Class B common stock will be available for sale in the public market as follows:

Upon completion of this offering and the concurrent private placement, stockholders owning an aggregate of up to 144,907,822 shares of our Class B common stock and 5,020,525 shares of our Class A common stock will be entitled, under our investors’ rights agreement, to require us to register shares owned by them for public sale in the United States. In addition, we intend to file a registration statement to register shares reserved for future issuance under our equity compensation plans. Upon effectiveness of that registration statement, subject to the satisfaction of applicable exercise periods and the expiration or waiver of the market standoff agreements and lock-up agreements referred to above, the shares issued upon exercise of outstanding stock options or upon settlement of outstanding RSU awards will be available for immediate resale in the United States in the open market.

Sales of our shares as restrictions end or pursuant to registration rights may make it more difficult for us to sell equity securities in the future at a time and at a price that we deem appropriate. These sales also could cause the trading price of our Class A common stock to fall and make it more difficult for you to sell shares of our Class A common stock.

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If you purchase our Class A common stock in this offering, you will incur immediate and substantial dilution.

The initial public offering price is substantially higher than the pro forma as adjusted net tangible book value per share of our outstanding common stock of $1.03 per share as of December 31, 2017. Investors purchasing shares of our Class A common stock in this offering will pay a price per share that substantially exceeds the book value of our tangible assets after subtracting our liabilities. As a result, investors purchasing Class A common stock in this offering will incur immediate dilution of $19.97 per share, based on the initial public offering price of $21.00 per share.

This dilution is due to the substantially lower price paid by our investors who purchased shares prior to this offering as compared to the price offered to the public in this offering, and any previous exercise of stock options granted to our service providers. In addition, as of December 31, 2017, options to purchase 4,959,492 shares of our Class B common stock with a weighted-average exercise price of approximately $10.52 per share were outstanding as well as 16,707,823 shares of our Class A common stock and 38,219,737 shares of our Class B common stock subject to RSUs. The exercise of any of these options and settlement of any of these RSUs would result in additional dilution. Our Board of Directors has approved the acceleration of the Performance Vesting Condition for 26,061,071 RSUs (which are included in the 38,219,737 shares of our Class B common stock subject to RSUs referenced above) for which the service condition was satisfied as of December 31, 2017, to occur upon the effectiveness of our registration statement related to this offering, which will result in the net issuance of 15,897,254 shares of our Class B common stock upon the RSU Settlement. As a result of the dilution to investors purchasing shares in this offering, investors may receive less than the purchase price paid in this offering, if anything, in the event of our liquidation.

We have broad discretion over the use of the net proceeds from this offering and the concurrent private placement and we may not use them effectively.

We cannot specify with any certainty the particular uses of the net proceeds that we will receive from this offering and the concurrent private placement. Our management will have broad discretion in the application of the net proceeds from this offering and the concurrent private placement, including for any of the purposes described in “Use of Proceeds,” and you will not have the opportunity as part of your investment decision to assess whether the net proceeds are being used appropriately. Because of the number and variability of factors that will determine our use of the net proceeds from this offering and the concurrent private placement, their ultimate use may vary substantially from their currently intended use. The failure by our management to apply these proceeds effectively could adversely affect our business, results of operations, and financial condition. Pending their use, we may invest our proceeds in a manner that does not produce income or that loses value. Our investments may not yield a favorable return to our investors and may negatively impact the price of our Class A common stock.

Delaware law and provisions in our restated certificate of incorporation and restated bylaws could make a merger, tender offer, or proxy contest difficult, thereby depressing the market price of our Class A common stock.

Our status as a Delaware corporation and the anti-takeover provisions of the Delaware General Corporation Law may discourage, delay, or prevent a change in control by prohibiting us from engaging in a business combination with an interested stockholder for a period of three years after the person becomes an interested stockholder, even if a change of control would be beneficial to our existing stockholders. In addition, our restated certificate of incorporation and restated bylaws contain provisions that may make the acquisition of our company more difficult, including the following:

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These anti-takeover defenses could discourage, delay, or prevent a transaction involving a change in control of our company. These provisions could also discourage proxy contests and make it more difficult for stockholders to elect directors of their choosing and to cause us to take other corporate actions they desire, any of which, under certain circumstances, could limit the opportunity for our stockholders to receive a premium for their shares of our capital stock, and could also affect the price that some investors are willing to pay for our Class A common stock.

Our amended and restated bylaws will designate a state or federal court located within the State of Delaware as the exclusive forum for substantially all disputes between us and our stockholders, and also provide that the federal district courts will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act, each of which could limit our stockholders’ ability to choose the judicial forum for disputes with us or our directors, officers, or employees.

Our amended and restated bylaws, which will become effective immediately prior to the completion of this offering, will provide that, unless we consent in writing to the selection of an alternative forum, the sole and

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exclusive forum for (1) any derivative action or proceeding brought on our behalf, (2) any action asserting a claim of breach of a fiduciary duty owed by any of our directors, officers, or other employees to us or our stockholders, (3) any action arising pursuant to any provision of the Delaware General Corporation Law, or the certificate of incorporation or the amended and restated bylaws or (4) any other action asserting a claim that is governed by the internal affairs doctrine shall be the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, the federal district court for the District of Delaware), in all cases subject to the court having jurisdiction over indispensable parties named as defendants.

Our amended and restated bylaws will also provide that the federal district courts of the United States of America will be the exclusive forum for resolving any complaint asserting a cause of action arising under the Securities Act.

Any person or entity purchasing or otherwise acquiring any interest in any of our securities shall be deemed to have notice of and consented to this provision. These exclusive-forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum of its choosing for disputes with us or our directors, officers, or other employees, which may discourage lawsuits against us and our directors, officers, and other employees. If a court were to find either exclusive-forum provision in our amended and restated bylaws to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving the dispute in other jurisdictions, which could harm our results of operations.

Affiliates of several of the underwriters in this offering may receive at least 5% of the net proceeds of this offering and may have an interest in this offering beyond customary underwriting discounts and commissions.

Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Deutsche Bank Securities Inc., and Merrill Lynch, Pierce, Fenner & Smith Incorporated are underwriters in this offering and their affiliates will receive at least 5% of the net proceeds of this offering in connection with the repayment of $213.4 million that is expected to be outstanding under our revolving credit facility immediately prior to the completion of this offering. As such, Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Deutsche Bank Securities Inc., and Merrill Lynch, Pierce, Fenner & Smith Incorporated are each deemed to have a “conflict of interest” under Rule 5121 of the Financial Industry Regulatory Authority Inc., or Rule 5121. Accordingly, this offering will be made in compliance with the applicable provisions of Rule 5121. This rule requires, among other things, that a “qualified independent underwriter” has participated in the preparation of, and has exercised the usual standards of “due diligence” with respect to, the registration statement. Allen & Company LLC has agreed to act as qualified independent underwriter for this offering and to undertake the legal responsibilities and liabilities of an underwriter under the Securities Act. Allen & Company LLC will not receive any additional fees for serving as qualified independent underwriter in connection with this offering. Although Allen & Company LLC has, in its capacity as qualified independent underwriter, participated in due diligence and the preparation of this prospectus and the registration statement of which this prospectus forms a part, we cannot assure you that this will adequately address all potential conflicts of interest. We have agreed to indemnify Allen & Company LLC against liabilities incurred in connection with acting as qualified independent underwriter, including liabilities under the Securities Act. Pursuant to FINRA Rule 5121, Goldman Sachs & Co. LLC, J.P. Morgan Securities LLC, Deutsche Bank Securities Inc., and Merrill Lynch, Pierce, Fenner & Smith Incorporated will not confirm sales of securities to any account over which it exercises discretionary authority without the prior written approval of the customer. See “Underwriting (Conflicts of Interest)” for additional information.

Our Class A common stock market price and trading volume could decline if securities or industry analysts do not publish research or publish inaccurate or unfavorable research about our business.

The trading market for our Class A common stock will depend in part on the research and reports that securities or industry analysts publish about us or our business. The analysts’ estimates are based upon their own opinions and are often different from our estimates or expectations. If one or more of the analysts who cover us downgrade our Class A common stock or publish inaccurate or unfavorable research about our business, the price

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of our securities would likely decline. If few securities analysts commence coverage of us, or if one or more of these analysts cease coverage of us or fail to publish reports on us regularly, demand for our securities could decrease, which might cause the price and trading volume of our Class A common stock to decline.

We do not intend to pay dividends for the foreseeable future.

We have never declared nor paid cash dividends on our capital stock. We currently intend to retain any future earnings to finance the operation and expansion of our business, and we do not expect to declare or pay any dividends in the foreseeable future. As a result, stockholders must rely on sales of their Class A common stock after price appreciation as the only way to realize any future gains on their investment. In addition, our revolving credit facility contains restrictions on our ability to pay dividends.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus contains forward-looking statements within the meaning of the federal securities laws, which statements involve substantial risks and uncertainties. Forward-looking statements generally relate to future events or our future financial or operating performance. In some cases, you can identify forward-looking statements because they contain words such as “may,” “will,” “should,” “expects,” “plans,” “anticipates,” “could,” “intends,” “target,” “projects,” “contemplates,” “believes,” “estimates,” “predicts,” “potential,” or “continue” or the negative of these words or other similar terms or expressions that concern our expectations, strategy, plans, or intentions. Forward-looking statements contained in this prospectus include, but are not limited to, statements about:

We caution you that the foregoing list may not contain all of the forward-looking statements made in this prospectus.

You should not rely upon forward-looking statements as predictions of future events. We have based the forward-looking statements contained in this prospectus primarily on our current expectations and projections about future events and trends that we believe may affect our business, financial condition, results of operations, and prospects. The outcome of the events described in these forward-looking statements is subject to risks,

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uncertainties and other factors described in the section titled “Risk Factors” and elsewhere in this prospectus. Moreover, we operate in a very competitive and rapidly changing environment. New risks and uncertainties emerge from time to time, and it is not possible for us to predict all risks and uncertainties that could have an impact on the forward-looking statements contained in this prospectus. We cannot assure you that the results, events, and circumstances reflected in the forward-looking statements will be achieved or occur, and actual results, events, or circumstances could differ materially from those described in the forward-looking statements.

The forward-looking statements made in this prospectus relate only to events as of the date on which the statements are made. We undertake no obligation to update any forward-looking statements made in this prospectus to reflect events or circumstances after the date of this prospectus or to reflect new information or the occurrence of unanticipated events, except as required by law. We may not actually achieve the plans, intentions, or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures, or investments we may make.

In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this prospectus, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements.

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INDUSTRY AND MARKET DATA

This prospectus contains estimates and information concerning our industry, including market size of the markets in which we participate, that are based on industry publications and reports. This information involves a number of assumptions and limitations, and you are cautioned not to give undue weight to these estimates. We have not independently verified the accuracy or completeness of the data contained in these industry publications and reports. The markets in which we operate are subject to a high degree of uncertainty and risk due to a variety of factors, including those described in the section titled “Risk Factors.” These and other factors could cause results to differ materially from those expressed in these publications and reports.

The source of certain statistical data, estimates and forecasts contained in this prospectus are the following independent industry publications or reports:

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USE OF PROCEEDS

We estimate that the net proceeds to us from the sale of shares of our Class A common stock in this offering and the concurrent private placement will be approximately $631.2 million, based upon the initial public offering price of $21.00 per share and after deducting underwriting discounts and commissions and estimated offering expenses payable by us. If the underwriters’ option to purchase additional shares of our Class A common stock from us is exercised in full, we estimate that the net proceeds to us would be approximately $739.6 million, after deducting underwriting discounts and commissions and estimated offering expenses payable by us. We will not receive any of the proceeds from the sale of Class A common stock in this offering by the selling stockholders.

The principal purposes of this offering are to increase our capitalization and financial flexibility, create a public market for our Class A common stock, and enable access to the public equity markets for us and our stockholders.

We intend to use a portion of the net proceeds we receive from this offering and the concurrent private placement to repay $213.4 million that is expected to be outstanding immediately prior to the completion of this offering under our revolving credit facility, which we intend to draw down prior to the completion of this offering to satisfy tax withholding and remittance obligations of $213.4 million related to the RSU Settlement. See the section titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources” for additional information regarding our revolving credit facility.

We also intend to use the net proceeds we receive from this offering and the concurrent private placement for general corporate purposes, including working capital, operating expenses, and capital expenditures. Additionally, we may use a portion of the net proceeds we receive from this offering and the concurrent private placement to acquire businesses, products, services, or technologies. However, we do not have agreements or commitments for any material acquisitions at this time. We cannot specify with certainty the particular uses of the net proceeds that we will receive from this offering and the concurrent private placement. Accordingly, we will have broad discretion in using these proceeds. Pending the use of proceeds from this offering as described above, we may invest the net proceeds that we receive in this offering and the concurrent private placement in short-term, investment grade, interest-bearing instruments.

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DIVIDEND POLICY

We have never declared or paid any cash dividends on our capital stock. We currently intend to retain any future earnings and do not expect to pay any dividends in the foreseeable future. Any future determination to declare cash dividends will be made at the discretion of our Board of Directors, subject to applicable laws, and will depend on a number of factors, including our financial condition, results of operations, capital requirements, contractual restrictions, general business conditions, and other factors that our Board of Directors may deem relevant. In addition, the terms of our revolving credit facility place certain limitations on the amount of cash dividends we can pay, even if no amounts are currently outstanding.

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CAPITALIZATION

The following table sets forth cash and cash equivalents, as well as our capitalization, as of December 31, 2017, as follows:

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The pro forma as adjusted information set forth in the table below is illustrative only and will be adjusted based on the actual initial public offering price and other terms of this offering determined at pricing. You should read this table together with our consolidated financial statements and related notes, and the sections titled “Selected Consolidated Financial and Other Data” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations” that are included elsewhere in this prospectus.

If the underwriters’ option to purchase additional shares of our Class A common stock from us were exercised in full, pro forma as adjusted cash and cash equivalents, additional paid-in capital, total stockholders’ equity, total capitalization, and Class A shares outstanding as of December 31, 2017, would be $956.0 million, $2,090.2 million, $628.9 million, $628.9 million, and 57,979,153 shares, respectively.

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The number of shares of our Class A common stock, Class B common stock, and Class C common stock that will be outstanding after this offering and the concurrent private placement is based on 11,817,248 shares of our Class A common stock (including the Capital Stock Conversions), 348,501,449 shares of our Class B common stock (including the Capital Stock Conversions and the RSU Settlement), and no shares of our Class C common stock outstanding as of December 31, 2017, and excludes the following:

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Our 2018 Plan and ESPP each provides for annual automatic increases in the number of shares of our Class A common stock reserved thereunder, and our 2018 Plan also provides for increases to the number of shares of our Class A common stock that may be granted thereunder based on shares under our 2008 Equity Incentive Plan, or our 2008 Plan, and 2017 Plan that expire, are forfeited, or otherwise repurchased by us, as more fully described in the section titled “Executive Compensation—Employee Benefits and Stock Plans.” Additionally, if and when our Board of Directors determines to use our 2018 Class C Plan and Class C ESPP, such plans will provide for annual automatic increases in the number of shares of our Class C common stock reserved thereunder.

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DILUTION

If you invest in our Class A common stock in this offering, your ownership interest will be diluted to the extent of the difference between the initial public offering price per share of our Class A common stock and the pro forma as adjusted net tangible book value per share of our common stock immediately after this offering and the concurrent private placement. Net tangible book value dilution per share to new investors represents the difference between the amount per share paid by purchasers of shares of our Class A common stock in this offering and the pro forma as adjusted net tangible book value per share of our common stock immediately after completion of this offering and the concurrent private placement.

Net tangible book value per share is determined by dividing our total tangible assets less our total liabilities by the number of shares of our common stock outstanding. Our historical net tangible book value as of December 31, 2017, was $(13.0) million, or $(0.04) per share. Our pro forma net tangible book value as of December 31, 2017, was $(226.5) million, or $(0.63) per share, based on the total number of shares of our Class A common stock and Class B common stock outstanding as of December 31, 2017, after giving effect to the Capital Stock Conversions and the RSU Settlement.

After giving effect to the sale by us of 31,584,314 shares of our Class A common stock in this offering and the concurrent private placement at the initial public offering price of $21.00 per share and after deducting underwriting discounts and commissions and estimated offering expenses payable by us, our pro forma as adjusted net tangible book value as of December 31, 2017, would have been $404.7 million, or $1.03 per share. This represents an immediate increase in pro forma net tangible book value of $1.66 per share to our existing stockholders and an immediate dilution in pro forma net tangible book value of $19.97 per share to investors purchasing shares of our Class A common stock in this offering at the initial public offering price. The following table illustrates this dilution:

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If the underwriters’ option to purchase additional shares of our Class A common stock from us is exercised in full, the pro forma as adjusted net tangible book value per share of our common stock, as adjusted to give effect to this offering and the concurrent private placement, would be $1.29 per share, and the dilution in pro forma net tangible book value per share to new investors purchasing shares of our Class A common stock in this offering would be $19.71 per share.

The following table presents, as of December 31, 2017, after giving effect to the Capital Stock Conversions and the RSU Settlement, the differences between the existing stockholders and the new investors purchasing shares of our Class A common stock in this offering and the concurrent private placement with respect to the number of shares purchased from us, the total consideration paid or to be paid to us, which includes net proceeds received from the issuance of our Class A common stock and the average price per share paid or to be paid to us at the initial public offering price of $21.00 per share, before deducting underwriting discounts and commissions and estimated offering expenses payable by us:

Except as otherwise indicated, the above discussion and tables assume no exercise of the underwriters’ option to purchase additional shares of our Class A common stock from us. If the underwriters’ option to purchase additional shares of our Class A common stock were exercised in full, our existing stockholders would own 90.7% and our new investors would own 9.3% of the total number of shares of our common stock outstanding upon completion of this offering and the concurrent private placement.

Sales by the selling stockholders in this offering will cause the number of shares held by existing stockholders to be reduced to 351,141,106 shares, or 89.6% of the total number of shares of our common stock outstanding following the completion of this offering and the concurrent private placement, and will increase the number of shares held by new investors to 40,761,905 shares, or 10.4% of the total number of shares outstanding following the completion of this offering and the concurrent private placement.

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The number of shares of our Class A common stock, Class B common stock, and Class C common stock that will be outstanding after this offering and the concurrent private placement is based on 11,817,248 shares of our Class A common stock (including the Capital Stock Conversions), 348,501,449 shares of our Class B common stock (including the Capital Stock Conversions and the RSU Settlement) and no shares of our Class C common stock outstanding as of December 31, 2017, and excludes the following:

Our 2018 Plan and ESPP each provides for annual automatic increases in the number of shares of our Class A common stock reserved thereunder, and our 2018 Plan also provides for increases to the number of shares of our Class A common stock that may be granted thereunder based on shares under our 2008 Equity Incentive Plan, or our 2008 Plan, and 2017 Plan that expire, are forfeited, or otherwise repurchased by us, as more fully described in the section titled “Executive Compensation—Employee Benefits and Stock Plans.” Additionally, if and when our Board of Directors determines to use our 2018 Class C Plan and Class C ESPP,

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such plans will provide for annual automatic increases in the number of shares of our Class C common stock reserved thereunder.

To the extent that any outstanding options to purchase our common stock are exercised, RSUs are settled or new awards are granted under our equity compensation plans, there will be further dilution to investors participating in this offering.

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SELECTED CONSOLIDATED FINANCIAL AND OTHER DATA

The following selected consolidated financial data should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the consolidated financial statements and related notes thereto included elsewhere in this prospectus. The consolidated statements of operations data for each of the years ended December 31, 2015, 2016, and 2017 and the consolidated balance sheet data as of December 31, 2016 and 2017, are derived from our audited consolidated financial statements that are included elsewhere in this prospectus. Our historical results are not necessarily indicative of our future results. The selected consolidated financial data in this section are not intended to replace the consolidated financial statements and related notes thereto included elsewhere in this prospectus and are qualified in their entirety by the consolidated financial statements and related notes thereto included elsewhere in this prospectus.

Consolidated Statements of Operations Data

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Consolidated Balance Sheet Data

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MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with the section titled “Selected Consolidated Financial and Other Data” and the consolidated financial statements and related notes thereto included elsewhere in this prospectus. This discussion contains forward-looking statements that involve risks and uncertainties. Our actual results could differ materially from those discussed below. Factors that could cause or contribute to such differences include, but are not limited to, those identified below and those discussed in the section titled “Risk Factors” included elsewhere in this prospectus.

Our Business

Our modern economy runs on knowledge. Today, knowledge lives in the cloud as digital content, and Dropbox is a global collaboration platform where more and more of this content is created, accessed, and shared with the world. We serve more than 500 million registered users across 180 countries.

Dropbox was founded in 2007 with a simple idea: Life would be a lot better if everyone could access their most important information anytime from any device. Over the past decade, we’ve largely accomplished that mission—but along the way we recognized that for most of our users, sharing and collaborating on Dropbox was even more valuable than storing files.

Our market opportunity has grown as we’ve expanded from keeping files in sync to keeping teams in sync. Today, Dropbox is well positioned to reimagine the way work gets done. We’re focused on reducing the inordinate amount of time and energy the world wastes on “work about work”—tedious tasks like searching for content, switching between applications, and managing workflows.

We’ve built a thriving global business with 11 million paying users. Our revenue was $603.8 million, $844.8 million, and $1,106.8 million in 2015, 2016, and 2017, respectively, representing an annual growth rate of 40% and 31%, respectively. We generated net losses of $325.9 million, $210.2 million, and $111.7 million in 2015, 2016, and 2017, respectively. We also generated positive free cash flow of $137.4 million and $305.0 million in 2016 and 2017, respectively, compared to negative free cash flow of $63.9 million in 2015.

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Our History

Since our founding, we’ve built one of the largest collaboration platforms in the world.

Our Subscription Plans

We generate revenue from individuals, teams, and organizations by selling subscriptions to our platform, which serve the varying needs of our diverse customer base. Of our 11 million paying users, approximately 30% use Dropbox for work on a Dropbox Business team plan, and we estimate that an additional 50% use Dropbox for work on an individual plan, collectively totaling approximately 80% of paying users. As of December 31,

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2017, approximately 92% of Fortune 500 companies had paying Dropbox users within their organization, and approximately 56% had at least one paying Dropbox Business team. We had more than 300,000 paying Dropbox Business teams as of December 31, 2017. Each Dropbox Business team represents a separately billed deployment that is managed through a single administrative dashboard. Each team must have a minimum of three users, but we also serve teams that can have more than tens of thousands of users. Customers can choose between an annual or monthly plan, with a small number of large organizations on multi-year plans. A majority of our customers opt for our annual plans. We typically bill our customers at the beginning of their respective terms and recognize revenue ratably over the term of the subscription period. International customers can pay in U.S. dollars or a select number of foreign currencies.

Individuals Dropbox Business Basic Plus Professional Standard Advanced Enterprise First launched 2008 2008 2017 2011 2017 2015 Number of users 1 user 1 user 1 user 3+ users 3+ users Large deployments Base price ($USD) per user Free $9.99/month $19.99/month $15.00/month $25.00/month Negotiated pricing $99/year $199/year $150/year $240/year Advanced sharing permissions Version history 30 days 30 days 120 days 120 days 120 days 120 days Smart Sync Showcase Team folders Unlimited API access Paper Storage 2GB 1TB 1TB 2TB As much as needed As much as needed Support Basic email support Priority email support Priority chat support Live chat support Business hours phone support 24/7 phone support Assigned account success manager Advanced admin & security features Remote device wipe Remote device wipe Admin console Managed groups Access permissions Account transfer tool HIPAA support Everything in Standard Device approval Audit log Tiered admin roles SSO integration Everything in Advanced EMM Network control Domain insights Integration support * Teams have unlimited API access to productivity and security partners but may be subject to a cap on API calls to data transport partners.

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Our premium subscription plans, such as Professional and Advanced, provide more functionality than other subscription plans and are offered at higher prices per user. Our Standard and Advanced subscription plans offer robust capabilities for businesses, and the vast majority of Dropbox Business teams, including those at Fortune 500 companies, purchase our Standard or Advanced subscription plans. While our Enterprise subscription plan offers more opportunities for customization, companies can subscribe to any of these team plans for their business needs.

Our Business Model

Drive new signups

We acquire users efficiently and at relatively low costs through word-of-mouth referrals, direct in-product referrals, and sharing of content.

Anyone can create a Dropbox account for free through our website or app and be up and running in minutes. These users often share and collaborate with other non-registered users, attracting new signups into our network. For example, many people use Dropbox for work and spread our platform by collaborating on projects or sharing content externally. We also acquire a small proportion of our registered users through paid marketing and distribution partnerships in which hardware manufacturers pre-install our software on their devices.

We have over 500 million registered users on our platform, of which over 100 million signed up since the beginning of 2017.

Increase conversion of registered users to our paid subscription plans

Dropbox Basic, the free version of our product, serves as a major funnel for conversions to our paid subscription plans. It fosters brand awareness, product familiarity, and organic adoption of Dropbox. When they purchase a subscription, our users gain access to premium features such as richer collaboration tools, administrative controls, and advanced security features, as well as larger storage capacity. We believe that our current registered user base represents a significant opportunity to increase our revenue. We estimate that approximately 300 million of our registered users have at least one characteristic that we believe makes them more likely than other registered users to pay over time. These characteristics include: (i) having signed up for Dropbox with a business domain email; (ii) having used specific types of computers or mobile devices to access our platform; or (iii) having signed up from certain countries in more developed markets in North America, Europe, and Asia Pacific, and having linked a desktop or laptop to our platform. Substantially all of our paying users share at least one of these characteristics. We’ve found that aggregate user activity metrics aren’t leading indicators of revenue or conversion. For that reason, we don’t comprehensively track user activity across the Dropbox platform for financial planning and forecasting purposes.

We generate over 90% of our revenue from self-serve channels—users who purchase a subscription through our app or website. We actively encourage our registered users to become paying users through in-product prompts and notifications, time-limited free trials of paid subscription plans, email campaigns, and lifecycle marketing.

During the fourth quarter of 2017, hundreds of millions of devices—including computers, phones, and tablets—were actively connected to the Dropbox platform. Because our users have installed Dropbox on many devices, we have multiple opportunities to inform them about new product experiences and premium subscription plans via in-product notifications, without any external marketing spend.

Our scale enables us to experiment and optimize the conversion marketing process. We run hundreds of product tests and targeted marketing campaigns simultaneously, and analyze usage patterns within our network to continually improve our user targeting and marketing messaging.

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Upgrade and expand existing customers

We offer a range of paid subscription plans, from Plus and Professional for individuals to Standard, Advanced, and Enterprise for teams. We analyze usage patterns within our network and run hundreds of targeted marketing campaigns to encourage paying users to upgrade their plans. For example, we prompt individual subscribers who collaborate with others on Dropbox to purchase our Standard or Advanced plans for a better team experience. They can do this by either joining an existing Dropbox Business team or by creating a new Dropbox Business team and inviting others to join. In 2017, over 40% of new Dropbox Business teams included a member who was previously a subscriber to one of our individual paid plans.

We believe that a large majority of individual customers use Dropbox for work, which creates an opportunity to significantly increase conversion to Dropbox Business team offerings over time. We also encourage existing Dropbox Business teams to purchase additional licenses or to upgrade to premium subscription plans.

Within an organization, Dropbox usage may be spread between a mix of Basic users, Plus and Professional subscribers, and one or more Dropbox Business teams. Our outbound sales team focuses on converting and consolidating these separate pockets of usage into a centralized deployment. Nearly all of our largest outbound deals originated as smaller self-serve deployments.

Our Attractive Cohort Economics

We define a cohort as all registered users who signed up for Dropbox in a given period of time. We track the total monthly subscription amount of all paying users in each cohort as of the end of the month, or the monthly subscription amount. For paying users who opt for our monthly plans, the monthly subscription amount is equal to the price of the monthly plan. For paying users who opt for our annual plans, which a majority of our users do, the monthly subscription amount is equal to the price of the annual plan divided by twelve. These amounts increase as more registered users in each cohort convert to paying users, paying users upgrade to premium subscription offerings, and team administrators purchase additional licenses. These amounts decrease when paying users terminate their subscriptions, downgrade their subscriptions to a lower tier, or team administrators reduce the number of licenses on their subscription plans. We continuously focus on adding new users and increasing the value we offer to them. As a result, each cohort of new users typically generates higher subscription amounts over time.

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The chart below reflects the monthly subscription amount from January 2013 to December 2017 of all paying users in each quarterly cohort, including those who signed up for our platform prior to 2013.

We continuously focus on adding new users and increasing the value we offer to them. As a result, each cohort of new users typically generates higher subscription amounts over time. For example, the monthly subscription amount generated by the January 2015 cohort doubled in less than three years after signup. We believe this cohort is representative of a typical cohort in recent periods.

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Moreover, as we continue to innovate and optimize our go-to-market strategy, we have successfully increased monetization for subsequent cohorts. Comparing January cohorts from the last three years, at virtually every point in time after signup, the January 2017 cohort generated a higher monthly subscription amount than the January 2016 cohort, which in turn generated a higher monthly subscription amount than the January 2015 cohort.

Our Global, Diversified Customer Base

The growing need for a unified home for content and the viral nature of our business have allowed us to scale globally. We have paying users across 180 countries, and we generated approximately half of our revenue in 2017 from customers outside the United States.

Our customer base is highly diversified, and in the periods presented, no customer accounted for more than 1% of our revenue. Our customers include individuals, teams, and organizations of all sizes, from freelancers and small businesses to Fortune 100 companies. They work across a wide range of industries, including professional services, technology, media, education, industrials, consumer and retail, and financial services. Within companies, our platform is used by all types of teams and functions, including sales, marketing, product, design, engineering, finance, legal, and human resources.

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Our Predictable Subscription Revenue

Taken together, our subscription revenue model, consistent cohort trends, self-serve monetization engine, and large and diversified global customer base resulted in linear and predictable revenue generation over the duration of the quarters presented in the chart below.

As of December 31, 2017, more than 80% of our annualized revenue came from existing individual users and Dropbox Business teams who were on our platform as of December 31, 2016.

As of December 31, 2017, our Annualized Net Revenue Retention for paying Dropbox Business customers was approximately 100%. Annualized Net Revenue Retention is the percentage of annualized revenue retained over a 365-day period, inclusive of changes in price, changes in number of licenses, upgrades and downgrades to different subscription plans, and churn. We calculate Annualized Net Revenue Retention by aggregating the annualized revenue from all paying Dropbox Business customers subscribing to a Dropbox Business plan at the beginning of the period, then aggregating the annualized revenue from those same Dropbox Business customers at the end of the period. For customers whose renewal is pending at the end of the period, we include their annualized revenue in the ending total if they resume payment within 30 days from the end of that period. Annualized Net Revenue Retention is equal to ending annualized revenue divided by beginning annualized revenue.

As of December 31, 2017, our blended Annualized Net Revenue Retention across the entire business, including individuals and Dropbox Business customers, was over 90%.

Key Factors Affecting Our Performance

We believe that the growth and future success of our business depends on many factors. While each of these factors presents significant opportunities for our business, they also pose important challenges that we must successfully address in order to sustain our growth and improve our results of operations.

Attract Users and Expand Relationships with Them. Our business model is based on attracting new users to our platform, converting registered users to paying users, and retaining and expanding paying users’

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subscriptions over time. Our continued success depends in part on our ability to offer compelling subscription plans with valuable capabilities, and to market these plans effectively to users. In addition, we must continue to provide a quality user experience to retain paying customers and encourage existing Dropbox Business teams to purchase additional licenses for their organizations over time. We intend to continue driving organic adoption by individual users and Dropbox Business teams through our self-serve model, and supplement this with our outbound sales force.

Continued Investment in Growth. We intend to continue to make focused investments to increase revenue and scale operations to support the growth of our business, and therefore expect expenses to increase. We plan to further invest in research and development as we hire employees in engineering, product, and design to enhance our platform and support the needs of our growing user base. We also plan to invest in sales and marketing activities to drive our self-serve business model and increase our brand awareness. We expect to incur additional general and administrative expenses to support our growth and our transition to being a publicly traded company. Further, we continue to make investments in our technical infrastructure to support user growth, and in our office locations to support employee growth, which will increase expenses and capital expenditures. As cost of revenue, operating expenses, and capital expenditures fluctuate over time, we may experience short-term, negative impacts to our results of operations and cash flows, but we are undertaking such investments in the belief that they will contribute to long-term growth.

Ongoing Innovation in a Rapidly Changing Environment. The market for content collaboration platforms is characterized by rapid technological change and frequent new product and service introductions. Our ability to acquire, retain, and upgrade paying users will depend in part on our ability to enhance our platform, introduce new features, and interoperate across an increasing range of devices, operating systems, and third-party applications. Certain features of our platform compete directly with products offered by Amazon, Apple, Atlassian, Box, Google, and Microsoft. We will need to continue to innovate in the face of this rapidly changing landscape to remain competitive.

Key Business Metrics

We review a number of operating and financial metrics, including the following key metrics to evaluate our business, measure our performance, identify trends affecting our business, formulate business plans, and make strategic decisions.

Paying users

We define paying users as the number of users who have active paid licenses for access to our platform as of the end of the period. One person would count as multiple paying users if the person had more than one active license. For example, a 50-person Dropbox Business team would count as 50 paying users, and an individual Dropbox Plus user would count as one paying user. If that individual Dropbox Plus user was also part of the 50-person Dropbox Business team, we would count the individual as two paying users.

We have experienced growth in the number of paying users across our products, with the vast majority of paying users for the periods presented coming from our self-serve channels.

The below table sets forth the number of paying users as of December 31, 2015, 2016, and 2017:

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Average revenue per paying user

We define average revenue per paying user, or ARPU, as our revenue for the period presented divided by the average paying users during the same period. For interim periods, we use annualized revenue, which is calculated by dividing the revenue for the particular period by the number of days in that period and multiplying this value by 365 days. Average paying users are calculated based on adding the number of paying users as of the beginning of the period to the number of paying users as of the end of the period, and then dividing by two.

Our ARPU declined for the year ended December 31, 2016, compared to the year ended December 31, 2015, primarily due to foreign currency fluctuations related to our sales that are denominated in foreign currencies. Our ARPU increased for the year ended December 31, 2017, compared to the year ended December 31, 2016, primarily due to an increased mix of sales towards our higher priced subscription plans, including our new Dropbox Business Advanced plan.

The below table sets forth our ARPU for the years ended December 31, 2015, 2016, and 2017.

Non-GAAP Financial Measure

In addition to our results determined in accordance with U.S. generally accepted accounting principles, or GAAP, we believe that free cash flow, or FCF, a non-GAAP financial measure, is useful in evaluating our liquidity.

Free cash flow

We define FCF as GAAP net cash provided by operating activities less capital expenditures. We believe that FCF is a liquidity measure and that it provides useful information regarding cash provided by operating activities and cash used for investments in property and equipment required to maintain and grow our business. FCF is presented for supplemental informational purposes only and should not be considered a substitute for financial information presented in accordance with GAAP. FCF has limitations as an analytical tool, and it should not be considered in isolation or as a substitute for analysis of other GAAP financial measures, such as net cash provided by operating activities. Some of the limitations of FCF are that FCF does not reflect our future contractual commitments, excludes investments made to acquire assets under capital leases, and may be calculated differently by other companies in our industry, limiting its usefulness as a comparative measure.

We have experienced an increase in our FCF as a result of an increase in net cash provided by operating activities, primarily due to our Infrastructure Optimization discussed below in “ —Recent Initiative,” increased sales in the periods presented, and a decrease in capital expenditures relating to infrastructure equipment and leasehold improvements for our office spaces. We expect our FCF to fluctuate in future periods as we purchase infrastructure equipment to support our user base and invest in our new and existing office spaces, including our new corporate headquarters, to support our plans for growth. These activities, along with certain increased operating expenses as described below, may result in a decrease in FCF as a percentage of revenue in future periods.

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The following is a reconciliation of FCF to the most comparable GAAP measure, net cash provided by operating activities:

Recent Initiative

Infrastructure Optimization

In recent years, we have taken several steps to improve the efficiency of the infrastructure that supports our platform. These efforts include an initiative that focused on migrating the vast majority of user data stored on the infrastructure of third-party service providers to our own lower cost, custom-built infrastructure in co-location facilities that we directly lease and operate. In order to host user data on our own infrastructure, we leased or purchased infrastructure that is depreciated within our cost of revenue. During the migration to our internal infrastructure, we duplicated our users’ data between our internal infrastructure and that of our third-party service providers, resulting in higher storage costs. We reduced this practice over time until we completed the migration in the fourth quarter of 2016. Related to this initiative, we no longer duplicate data between our internal infrastructure and that of any third-party service providers. We expect to continue to realize benefits from expanding our internal infrastructure due to our operating scale and lower unit costs.

Starting in 2016, we also took measures to manage the storage footprint of certain long-inactive Basic users, freeing up additional storage capacity. Specifically, we closed the accounts of certain Basic users who had not engaged in any activity on the Dropbox platform in the last year and did not respond to multiple e-mail inquiries from us regarding their inactivity. We continue to regularly take similar measures to manage long-inactive and non-responsive Basic user accounts, and our total registered user numbers do not include accounts that have been closed. This effort, along with additional usage optimizations in 2017, enabled us to continue operating our business within our existing infrastructure base without a need for extensive incremental capital expenditures and leasing activity.

These efforts are collectively referred to as our Infrastructure Optimization, and some are ongoing.

Our Infrastructure Optimization reduced unit costs and helped limit capital expenditures and associated depreciation. Combined with the concurrent increase in our base of paying users, we experienced a reduction in our cost of revenue, an increase in our gross margins, and an improvement in our free cash flow in the periods presented.

Components of Our Results of Operations

Revenue

We generate revenue from sales of subscriptions to our platform.

Revenue is recognized ratably over the related contractual term generally beginning on the date that our platform is made available to a customer. Our subscription agreements typically have monthly or annual contractual terms, although a small percentage have multi-year contractual terms. Our agreements are generally non-cancelable. We typically bill in advance for monthly contracts and annually in advance for contracts with terms of one year or longer. Amounts that have been billed are initially recorded as deferred revenue until the revenue is recognized.

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Our revenue is driven primarily by the number of paying users and the price we charge for access to our platform, which varies based on the type of plan to which a customer subscribes. We generate over 90% of our revenue from self-serve channels. No customer represented more than 1% of our revenue in the periods presented.

Cost of revenue and gross margin

Cost of revenue. Our cost of revenue consists primarily of expenses associated with the storage, delivery, and distribution of our platform for both paying users and Basic users. These costs, which we refer to as infrastructure costs, include depreciation of our servers located in co-location facilities that we lease and operate, rent and facilities expense for those datacenters, network and bandwidth costs, support and maintenance costs for our infrastructure equipment, and payments to third-party datacenter service providers. Cost of revenue also includes costs, such as salaries, bonuses, benefits, travel-related expenses, and stock-based compensation, which we refer to as employee-related costs, for employees whose primary responsibilities relate to supporting our infrastructure and delivering user support. Other non-employee costs included in cost of revenue include credit card fees related to processing customer transactions, and allocated overhead, such as facilities, including rent, utilities, depreciation on leasehold improvements and other equipment shared by all departments, and shared information technology costs. In addition, cost of revenue includes amortization of developed technologies, professional fees related to user support initiatives, and property taxes related to the datacenters.

We plan to continue increasing the capacity and enhancing the capability and reliability of our infrastructure to support user growth and increased use of our platform. We expect that cost of revenue, excluding the impact of certain stock-based compensation charges described in “—Significant Impacts of Stock-Based Compensation”, will increase in absolute dollars in future periods. In addition, as a result of certain stock-based compensation charges described in “—Significant Impacts of Stock-Based Compensation,” we expect our cost of revenue to increase significantly in absolute dollars in the quarter during which we complete this offering.

Gross margin. Gross margin is gross profit expressed as a percentage of revenue. Our gross margin may fluctuate from period to period based on the timing of additional capital expenditures and the related depreciation expense, or other increases in our infrastructure costs, as well as revenue fluctuations. As we continue to increase the utilization of our internal infrastructure, we generally expect our gross margin, excluding the impact of certain stock-based compensation charges described in “—Significant Impacts of Stock-Based Compensation”, to remain relatively constant in the near term and to increase modestly in the long term. Taking into account these charges, we expect our gross margin to decrease significantly in the quarter during which we complete this offering.

Operating expenses

Research and development. Our research and development expenses consist primarily of employee-related costs for our engineering, product, and design teams, and allocated overhead. Additionally, research and development expenses include internal development-related third-party hosting fees. We have expensed almost all of our research and development costs as they were incurred.

We plan to continue to hire employees for our engineering, product, and design teams to support our research and development efforts. We expect that research and development costs will increase in absolute dollars in future periods and, excluding the impact of certain stock-based compensation charges described in “—Significant Impacts of Stock-Based Compensation”, vary from period to period as a percentage of revenue.

Sales and marketing. Our sales and marketing expenses relate to both self-serve and outbound sales activities, and consist primarily of employee-related costs, brand campaign fees, lead generation fees, and allocated overhead. Sales commissions earned by our outbound sales team and the related payroll taxes, as well as commissions earned by third-party resellers that we consider to be incremental and recoverable costs of

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obtaining a contract with a user, are deferred and amortized over an estimated period of benefit of five years. Additionally, sales and marketing expenses include non-employee costs related to app store fees and fees payable to third-party sales representatives.

We plan to continue to invest in sales and marketing to grow our user base and increase our brand awareness, including marketing efforts to continue to drive our self-serve business model. The trend and timing of sales and marketing expenses will depend in part on the timing of marketing campaigns. We expect that sales and marketing expenses will increase in absolute dollars in future periods and, excluding the impact of certain stock-based compensation charges described in “—Significant Impacts of Stock-Based Compensation”, vary from period to period as a percentage of revenue.

General and administrative. Our general and administrative expenses consist primarily of employee-related costs for our legal, finance, human resources, and other administrative teams, as well as certain executives. In addition, general and administrative expenses include allocated overhead, outside legal, accounting and other professional fees, and non-income based taxes.

We expect to incur additional general and administrative expenses to support the growth of the Company as well as our transition to being a publicly traded company, which includes the recognition of stock-based compensation expense related to grants of restricted stock made to our co-founders. We expect that general and administrative expenses will increase in absolute dollars in future periods and, excluding the impact of certain stock-based compensation charges described in “—Significant Impacts of Stock-Based Compensation”, vary from period to period as a percentage of revenue.

As a result of certain stock-based compensation charges described in “—Significant Impacts of Stock-Based Compensation,” we expect our research and development, sales and marketing, and general and administrative expenses to increase significantly in absolute dollars and as a percentage of revenue in the quarter during which we complete this offering.

Interest expense, net

Interest expense, net consists primarily of interest expense related to our capital lease obligations for infrastructure and our imputed financing obligation for our obligation to the legal owner of our previous corporate headquarters, partially offset by interest income earned on our money market funds classified as cash and cash equivalents.

Other income (expense), net

Other income (expense), net consists of other non-operating gains or losses, including those related to ongoing subleases and foreign currency transaction gains and losses.

Provision for income taxes

Provision for income taxes consists primarily of U.S. federal and state income taxes and income taxes in certain foreign jurisdictions in which we conduct business. For the periods presented, the difference between the U.S. statutory rate and our effective tax rate is primarily due to the valuation allowance on deferred tax assets. Our effective tax rate is also impacted by earnings realized in foreign jurisdictions with statutory tax rates lower than the federal statutory tax rate. We maintain a full valuation allowance on our net deferred tax assets for federal, state, and certain foreign jurisdictions as we have concluded that it is not more likely than not that the deferred assets will be realized.

As of December 31, 2017, we had $312.2 million of federal and $143.0 million of state net operating loss carryforwards available to reduce future taxable income, which will begin to expire in 2031 for federal and 2030

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for state tax purposes. As of December 31, 2017, we also had $289.3 million of foreign net operating loss carryforwards available to reduce future taxable income, which will carryforward indefinitely. In addition, we had $22.9 million of foreign acquired net operating losses, which will carryforward indefinitely. It is possible that we will not generate taxable income in time to use these net operating loss carryforwards before their expiration. In addition, under Section 382 and 383 of the Internal Revenue Code of 1986, as amended, or the Code, if a corporation undergoes an “ownership change,” the corporation’s ability to use its pre-change net operating loss carryforwards and other pre-change attributes, such as research tax credits, to offset its post-change income may be limited. In general, an “ownership change” will occur if there is a cumulative change in our ownership by “5-percent shareholders” that exceeds 50 percentage points over a rolling three-year period. Similar rules may apply under state tax laws. We performed a study for the period through December 31, 2017, and determined that no ownership changes exceeding 50 percentage points have occurred. Our ability to use net operating loss and tax credit carryforwards to reduce future taxable income and liabilities may be subject to annual limitations as a result of ownership changes from January 1, 2018, and subsequent years, or as a result of this offering.

The Tax Cuts and Jobs Act, or the Tax Reform Act, was enacted on December 22, 2017 and provides for significant changes to U.S. tax law. Among other provisions, the Tax Reform Act reduces the U.S. corporate income tax rate to 21% effective in 2018. The Tax Reform Act also contains a number of provisions that may impact us in future years. Since the Tax Reform Act was recently finalized and ongoing guidance and accounting interpretation is expected over the next twelve months, we have made certain provisional accounting estimates, as permitted under Staff Accounting Bulletin No. 118, and continue to analyze our accounting policies in this area. The U.S. Treasury Department, the IRS, and other standard-setting bodies could interpret or issue guidance on how provisions of the Tax Reform Act will be applied or otherwise administered that is different from our interpretation. As we complete our analysis of the Tax Reform Act, collect and prepare necessary data, and interpret any additional guidance, the we may make adjustments to provisional amounts that we have recorded that may be material in the period in which the adjustments are made. The final accounting analysis will occur no later than one year from the date the Tax Reform Act was enacted.

As a result of the reduction in the corporate rate, we have remeasured our U.S. deferred tax assets and liabilities as of December 31, 2017 to reflect the lower rate expected to apply when these temporary differences reverse. We provisionally estimate that the remeasurement resulted in a reduction in deferred tax assets of $63.1 million, which was fully offset by a corresponding change to our valuation allowance. Although the tax rate reduction is known, we have not collected all of the necessary data to complete our analysis of the effect of the Tax Reform Act on the underlying deferred taxes and as such, the amounts recorded as of December 31, 2017 are provisional. However, we anticipate that any adjustment to provisional amounts recorded would be fully offset by a corresponding change to our valuation allowance.

The Tax Reform Act repeals the corporate alternative minimum tax, or AMT, effective beginning in 2018 and permits AMT credit carryforwards to be refunded to the extent unused through 2021. Since we do not anticipate the use of these credits to reduce future federal taxes, we recognized an income tax benefit and established an income tax receivable to reflect anticipated refunds of $1.4 million for our 2016 AMT credit carryforward during the year ended December 31, 2017. We have not collected all of the necessary data to complete our analysis of the classification of the AMT tax credit as a receivable and as such, the amounts recorded as an income tax receivable as of December 31, 2017 are provisional.

The Tax Reform Act also provides for a transition to a new territorial system of taxation and generally requires companies to include certain untaxed foreign earnings of non-U.S. subsidiaries into taxable income in 2017, or the Transition Tax. As a result of the cumulative deficits in our foreign subsidiaries, we estimate that we will have no Transition Tax inclusion.

We continue to evaluate our accounting policy for recording deferred taxes, if any, that would arise as a result of other new provisions including the global intangible low-taxed income tax and the base erosion tax

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regimes established under the Tax Reform Act. This evaluation will be completed no later than one year from the date the Tax Reform Act was enacted.

Results of Operations

The following tables set forth our results of operations for the periods presented and as a percentage of our total revenue for those periods:

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Comparison of the year ended December 31, 2016 and 2017

Revenue

Revenue increased $262.0 million or 31% during 2017, as compared to 2016. This increase was primarily due to a 25% increase in the number of paying users between periods. The average revenue per paying user also increased slightly between periods primarily due to an increased mix of sales towards our higher priced subscription plans, including our new Dropbox Business Advanced plan.

Cost of revenue, gross profit, and gross margin

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Cost of revenue decreased $21.7 million or 6% during 2017, as compared to 2016, primarily due to a $35.1 million decrease in our infrastructure costs due to our Infrastructure Optimization. Further, the decrease in cost of revenue was due to a $5.9 million decrease in amortization of developed technologies, as certain intangible assets became fully amortized during 2016. These decreases were partially offset by an increase of $11.0 million in employee-related expenses, which was due to headcount growth, an increase of $5.3 million in credit card transaction fees due to higher sales and an increase of $3.0 million in professional fees for user support.

Our gross margin increased from 54% during 2016 to 67% during 2017, primarily due to a 31% increase in our revenue during the period and our Infrastructure Optimization.

Research and development

Research and development expenses increased $90.6 million or 31% during 2017, as compared to 2016, primarily due to an increase of $64.7 million in employee-related expenses, which was due to headcount growth. Further, the increase in research and development expense was due to an increase of $14.1 million in overhead-related costs and an increase of $4.5 million in internal development-related third-party hosting fees.

Sales and marketing

Sales and marketing expenses increased $63.4 million or 25% during 2017, as compared to 2016, primarily due to an increase of $40.9 million in variable spend related to brand campaign fees, lead generation fees, and third-party sales representative fees. In addition, sales and marketing expenses increased due to $17.8 million in employee-related expenses excluding stock-based compensation, which was due to headcount growth. Stock-based compensation decreased $10.9 million due to the modification of an executive stock grant during 2016, that resulted in a charge of $18.8 million in that prior period. Sales and marketing expenses also increased $8.4 million due to app store fees as a result of increased sales and $7.6 million due to overhead-related costs.

General and administrative

General and administrative expenses increased $49.9 million or 46% during 2017, as compared to 2016, primarily due to an increase of $17.3 million in non-income based taxes as a result of the growth in our business. General and administrative expenses during 2016 included a $12.4 million benefit relating to a non-income based tax ruling. In addition, employee-related expenses increased $13.3 million during 2017, as compared to 2016,

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due to headcount growth, and other general and administrative expenses increased $11.3 million related to the funding of the Dropbox Charitable Foundation. Included in this amount was an equity-based charitable contribution of $9.4 million and cash contributions of $1.9 million. Further, general and administrative expenses increased $4.3 million due to legal-related expenses and accounting services.

Interest expense, net

Interest expense, net decreased $5.4 million during 2017, as compared to 2016, primarily due to a decrease in interest expense of $3.3 million due to fewer assets acquired under capital leases. In addition, interest income from our money market funds increased by $2.1 million.

Other income (expense), net

Other income (expense), net increased $8.3 million during 2017, as compared to 2016, primarily due to an increase of $8.6 million in foreign currency gains related to monetary assets and liabilities denominated in euros and British pound sterling.

Provision for income taxes

Provision for income taxes decreased by $5.0 million during 2017 as compared to 2016, primarily as a result of a change in our U.S. AMT position. We were subject to U.S. AMT during 2016, and we do not expect to be subject to U.S. AMT during 2017. In addition, as a result of the repeal of AMT as part of the Tax Reform Act, we recognized a benefit and established a receivable in 2017 to reflect anticipated refunds of our 2016 AMT credit carryforward.

Comparison of the year ended December 31, 2015 and 2016

Revenue

Revenue increased $241.0 million or 40% during 2016 as compared to 2015. This increase was primarily due to a 35% increase in the number of paying users between periods. The average revenue per paying user also decreased slightly between periods.

Cost of revenue, gross profit, and gross margin