"Aren't you worried that it takes few weeks(days?) of coding for dropbox team and one update for your solution to become obsolete?" Wouldnt this logic apply to every project? What if Google Docs just builds a dropbox type app on top of it? Google certainly had more resources and superb tech talent. I think all companies have their focus and are already very busy getting their product right. If you think there is a need for which you have the right solution - build it. Who knows - Dropbox might just buy you out.