Apart from Dropbox, Box faces increasing competition from Microsoft Corp's (MSFT.O) OneDrive, which is offered free when users sign up for its Office apps, Apple Inc's (AAPL.O) iCloud, and Google Inc's (GOOGL.O) Google Drive.
Box offers 10 gigabytes of free online storage and charges fees for additional space.
To help it compete, Box offers specialized storage options such as digital versions of X-rays for drugmakers.