Comment by TeMPOraL

> but I've been repeatedly amazed at the scale of the opportunity. People working cross-mobile/desktop must be a big part of it.

Or just multiple computers. Also don't forget file sharing and collaboration.

I'm a long-time Dropbox user, and my first use cases were, in order:

- shared folders with friends at university, when we were working on projects together

- shared folder for myself between personal computer and a station at work

Nowadays I use it mostly as a way to sync up my time/task tracking (in Emacs/org-mode) between multiple machines and mobile devices.

OTOH, my SO regularly uses Dropbox at work to exchange bundles of 200+MB files with other companies, and it's telling - there really is no better, safer solution for a regular user to send someone larger files when they no longer fit in an e-mail.