Dropbox (service)

Dropbox is a file hosting service operated by Dropbox, Inc., headquartered in San Francisco, California, that offers cloud storage, file synchronization, and client software. Dropbox allows users to create a special folder on each of their computers, which Dropbox then synchronizes so that it appears to be the same folder (with the same contents) regardless of which computer is used to view it. Files placed in this folder also are accessible through a website and mobile phone applications.

Dropbox, Inc., was founded in 2007 by Drew Houston and Arash Ferdowsi, as a Y Combinator startup company.

Dropbox provides client software for Microsoft Windows, Mac OS X, Linux, Android, iOS, BlackBerry OS and web browsers, as well as unofficial ports to Symbian, Windows Phone, and MeeGo.

History
According to Dropbox, founder Drew Houston conceived the idea after repeatedly forgetting his USB flash drive while he was a student at MIT. He says that existing services at the time "suffered problems with Internet latency, large files, bugs, or just made me think too much". He began making something for his personal use, but then realized that it could benefit others with the same problems. Houston founded Dropbox, Inc. in June 2007, and shortly thereafter secured seed funding from Y Combinator. Dropbox officially launched at 2008's TechCrunch50, an annual technology conference.

Due to trademark disputes between Proxy, Inc. and Evenflow (Dropbox's parent company), Dropbox's official domain name was "getdropbox.com" until October 2009, when they acquired their current domain, "dropbox.com".

OPSWAT reported in their December 2011 market share report that Dropbox held 14.14% of the worldwide backup client market, based on number of installations.

In May 2011, Dropbox struck deals with Japanese mobile service providers Softbank and Sony Ericsson. As per the terms of the deal Dropbox will come preloaded on their mobile telephones.

In May 2010, Dropbox users in China were unable to access Dropbox. Later, Dropbox confirmed they had been blocked by the Chinese government. Due to the fact that the censorship usually focuses on popular services only, many considered this evidence of Dropbox's rapidly rising popularity and international user base. , the website is still blocked in China, but locally installed applications are usable with some ISPs.

, Dropbox had more than 50 million registered users.

In April 2012, Dropbox announced a new feature allowing users to automatically upload photographs or videos from camera, tablet, SD card, or smartphone. Users will be given up to 3 GB (initially 5 GB) extra space to accommodate the photographs and videos uploaded in this fashion, but the space is permanently added to the user's allowance and is not restricted to pictures. It is viewed as a move against Google's recently launched Google Drive and Microsoft's SkyDrive.

, Facebook and Dropbox integrated to allow group users to share files to Facebook Groups using Dropbox’s cloud-based storage system. The feature allows users to directly share inside Facebook's group pages without exiting the Facebook domain. This did not replace the built in Facebook uploading feature, but added to it for any files that were already uploaded to their Dropbox storage account.

On November 12, 2012, Dropbox announced it had reached 100 million users. On December 19, 2012, Dropbox acquired Snapjoy, which provided a service for aggregating, archiving and viewing all digital photographs taken with cameras, phones, or popular photo applications. Financial terms were not released at the time of the acquisition.

As of February 2013, Dropbox was responsible for 0.29% of all worldwide Internet traffic.

On March 15, 2013, Dropbox acquired the email management application for iOS Mailbox.

On July 20, 2013, Dropbox acquired mobile coupon startup Endorse.

On November 13, 2013, Dropbox announced it had reached 200 million users, and announced changes to "Dropbox for Business".

On November 21, 2013, Dropbox released new application versions for iOS. The new design has a cleaner and simpler user interface which brings the app in-line with other iOS 7 offerings.

Financials
Dropbox is funded by Sequoia Capital, Accel Partners, and Amidzad. Starting in mid-2009, they began releasing new features gradually to help measure customer interest, a Lean Startup technique.

Dropbox has received total venture capital funding of US$257.2 million from several investors, including Y Combinator, Sequoia Capital, and Accel Partners.

In 2011, technology entrepreneur Praveen Yajman speculated that Dropbox's valuation was more than $1 billion. TechCrunch, VentureBeat, Business Insider, and Financial Post speculated that Dropbox's valuation could be up to $5 to $10 billion, while its 2011 revenue was expected to be $240 million.

On April 3, 2012, Dropbox announced Bono and The Edge, two members of the Irish rock band U2, were individual investors in the company.

Business model
Dropbox uses a freemium business model, where users are offered a free account with a set storage size and paid subscriptions for accounts with more capacity.

The desktop client has no restriction on individual file size; files uploaded via the web site are limited to no more than 10 GB per file. To prevent free users from creating multiple linked free accounts, Dropbox includes the content of shared folders when totaling the amount of space used on the account.

Technology
Both the Dropbox server and desktop client software are primarily written in Python. The desktop client uses GUI toolkits such as wxWidgets and Cocoa. Other notable Python libraries include Twisted, ctypes, and pywin32. Dropbox ships and depends on the librsync binary-delta library (which is written in C).

The Dropbox client enables users to drop any file into a designated folder that is then synchronized with Dropbox's Internet service and to any other of the user's computers and devices with the Dropbox client. Users may also upload files manually through a web browser.

Dropbox client supports synchronization and sharing along with personal storage. It supports revision history, so files deleted from the Dropbox folder may be recovered from any of the synced computers. Dropbox supports multi-user version control, enabling several users to edit and re-post files without overwriting versions. The version history is by default kept for 30 days, with an unlimited version called "Pack-Rat" available for purchase.

The version history is paired with the use of delta encoding technology. When a file in a user's Dropbox folder is changed, Dropbox only uploads the pieces of the file that are changed when synchronizing, when possible.

Dropbox uses Amazon's S3 storage system to store the files; though Houston has stated that Dropbox may switch to a different storage provider at some point in the future. It also uses SSL transfers for synchronization and stores the data via AES-256 encryption, though this is done with Dropbox's own encryption keys, and not the users'.

Dropbox also provides a technology called LAN sync, which allows computers on a local area network to securely download files locally from each other instead of always hitting the central servers. LANSync was developed by Dropbox Engineer Paul Bohm.

Functionality
Users have devised a number of uses for and mashups of the technology that expand Dropbox's functionality. These include: sending files to a Dropbox via Gmail; using Dropbox to sync IM chat logs; BitTorrent management; password management; remote application launching and system monitoring; and as a free Web hosting service.

Add-ons
There are official and unofficial Dropbox add-ons, mostly created by the Dropbox community. These add-ons are both in the form of web services such as SendToDropbox (which allows users to email files to their Dropboxes), Backup Box (which facilitates online backup of FTP, Git, MySQL, and other services to Dropbox accounts), and desktop applications such as MacDropAny (which allows users to sync any folder on their computer with Dropbox).

There are a number of client applications for operating systems that Dropbox does not officially support, such as Maemo, Symbian, Windows Phone and webOS.

An open source tool called Dropship provided unauthenticated access to Dropbox-hosted files by using the Dropbox API to access files by their hash. Dropbox attempted to suppress this project by requesting its suspension where it was being hosted, and by issuing an erroneous DMCA takedown notice, later said by Dropbox co-founder Arash Ferdowsi to have been incorrectly auto-generated by a support tool used to ban the public links.

Reception
Dropbox has been praised by many publications—including The Economist, New York Times, PC Magazine, and The Washington Post—for its simple design and ease of use. It has also received several awards, including the Crunchie Award in 2009 for Best Internet Application, and Macworld's 2009 Editor's Choice Award. It was nominated for a 2010 Webby Award, and for the 2010 Mac Design Awards by Ars Technica.

Dropbox has been named as the world's fifth most valuable web startup after Facebook, Twitter, Zynga, and Groupon,  has been described as Y Combinator's most successful investment to date, and is among the top 10 iPhone most popular apps of all time, according to TechCrunch. It was voted among the top 10 Android apps of all time, according to ZDNet, said to be one of the top 50 emerging companies by TIEcon, and called one of the 20 best startups of Silicon Valley. Drew Houston was called the best young tech entrepreneur by Business Week, and he and co-founder Arash Ferdowsi were named among the top 30 under 30 entrepreneurs by inc.com. In January 2012, the company was named startup of the year by TechCrunch.

Privacy concerns
Dropbox has been criticized by the independent security researcher Derek Newton, who said that Dropbox stores authentication secret (not password) on disk in plain-text (this was fixed in 1.2.48) and by the software engineer Miguel de Icaza, who says that Dropbox's terms of service contradict its privacy policy, and that the company's famous claim "Dropbox employees aren't able to access user files" is a lie.

In May 2011, a complaint was filed with the U.S. FTC alleging Dropbox misled users about the privacy and security of their files. At the heart of the complaint was the policy of "deduplication", where the system checks if a file has been uploaded before by any other user, and links to the existing copy if so; and the policy of using a single AES-256 key for every file on the system so Dropbox can (and does, for deduplication) look at encrypted files stored on the system, with the consequence that any intruder who gets the key (as well as Dropbox employees) could decrypt any file if they had access to Dropbox's backend storage infrastructure.

On June 20, 2011, TechCrunch reported that all Dropbox accounts could be accessed without password for four hours. This was later widely reported in the mainstream press and caused some doubt about Dropbox's "cloud" technology model. The error was caused by an authentication code update made at 1:54 p.m. Pacific Time; it was detected at 5:41 p.m. and immediately fixed. About 1% of Dropbox's users were logged in at that time; all sessions were immediately terminated. All users with compromised accounts were notified by email.

On July 31, 2012, Dropbox announced that an employee's account had been hacked, resulting in a number of Dropbox users' being spammed by email. In March 2013, users reported additional spam resulting from the July email leakage.

On June 6, 2013, The Guardian and The Washington Post publicized confidential documents suggesting Dropbox was being considered for inclusion in the National Security Agency's classified PRISM program of Internet surveillance.

On January 10, 2014, Dropbox experienced an outage, which the company publicly acknowledged on the company's home page: "We are aware of an issue currently affecting the Dropbox site". It continued, "We have identified the cause, which was the result of an issue that arose during routine internal maintenance, and are working to fix this as soon as possible. We apologize for any inconvenience." A hacker group called The 1775 Sec tweeted that it had compromised Dropbox's site to honor the anniversary of the Internet activist and computer programmer Aaron Swartz, who committed suicide in January 2013, and had stolen a list of emails, which they posted on the website Pastebin. However, Dropbox denied having been hacked, asserting the "hacker incident" was a hoax. The security researcher Wesley Mcgrew further pointed out the emails supposedly stolen from Dropbox have been found elsewhere on the web, and a known Anonymous Twitter account officially denied the hacker group's involvement.

Headquarters
Dropbox had premises at 760 Market Street in San Francisco, until moving to larger premises in July 2011.

From that date Dropbox's corporate headquarters are at Suite 400 on the fourth floor of the China Basin Landing building in San Francisco. The company occupies the fourth floor of the 1991 section of the facility, with 85600 sqft of space, and an option to take more space.