Box offers a cloud-storage and file-sharing application for businesses of all sizes. "Box helps companies work better with their employees, customers and partners using modern technologies that are cloud- and mobile-based," says Whitney Bouck, general manager of Box's enterprise division.\nCompany: Box, Inc.\nHeadquarters: Los Altos, Calif.\nEmployees: 750\nRevenue: not disclosed\nCEO: Aaron Levie\nWhat They Do: Box, a cloud-storage and file-sharing service, lets employees do document-centric collaboration with each other and with outside parties. The Box service can be accessed from computer browsers and mobile apps for all major platforms. Box also provides IT management and security features.\nBox Bags Fortune 500 CustomersThe privately-held company, founded in 2005, has raised almost $300 million in funding and is backed by well-known investors such as Draper Fisher Jurvetson and Andreessen Horowitz. Over 150,000 businesses use Box, including more than 90 percent of the Fortune 500. Revenue grew almost 150 percent last year.The company has been enhancing the product's features, gaining footholds abroad, expanding its partner ecosystem and beefing up its data center infrastructure. Its CEO told Bloomberg News that the company may go public next year.Cloud Service Does Offer IT ChallengesAs when considering other cloud software, prospective Box customers need to decide whether they're comfortable storing their files in the vendor's data centers, says Rob Koplowitz, a Forrester Research analyst.Enterprises also must weigh the challenges of customizing cloud services like Box and integrating them with on-premises software, he says."That deep integration between cloud and on-premise properties is much more difficult to achieve with cloud software," Koplowitz says.CIOs must also consider that Box plays in a crowded market against products from larger rivals, such as Microsoft's SharePoint and EMC's Syncplicity, as well as against tools from Citrix, Good Technology, Accellion and YouSendIt."Box is a relatively new and small company compared with some of its competitors," says Gartner analyst Tom Eid. Plus, Box's collaboration and content-management functions are basic and lightweight compared to rival products, he says.How Box Scored Six FlagsSix Flags Entertainment, a theme park company, adopted Box several years ago because it needed a better collaboration tool for sharing large media files with its ad agency and other external parties.Previously the company had been using mostly email for that task, but the email network bogged down when people sent files larger than 10 megabytes, and the collaboration process was cumbersome."Box gives you a great environment for large files you need to collaborate on, or to distribute them externally," says Sean Andersen, Six Flags' director of interactive services.He says Box's user-friendly interface has helped spur its adoption."We keep Box organic. We don't force it on people. Our end users find it and come up with ways to use it, sometimes in ways that surprise me and our CIO," he says.Andersen says Box works well on desktop computers via the Web interface and on iOS devices via its mobile app. He also likes the IT administrative features such as single sign-on and enterprise directory integration.However, he also says he would like Box to add more integration hooks to on-premise storage systems, and to develop native, complementary applications for tasks like note-taking, task management, presentation sharing and PDF editing.Follow everything from CIO.com on Twitter @CIOonline, Facebook, Google + and LinkedIn.