Dropbox made itself a household name by giving away cloud storage.
The eight-year-old company, valued at $10 billion, had 300 million registered users a year ago; now it’s got 400 million.
Its two-year-old effort to make money from business users has been less impressive.
While Dropbox led the $904 million global market for business file-sharing last year with about a 24 percent share, No. 2 Box and No. 3 Microsoft each took about 21 percent and doubled their slice of the pie, growing almost twice as fast, according to researcher IDC.