This sort of backward reasoning doesn't work very well. Yes, Dropbox solves a hard problem. Plenty of other people have solved hard problems and didn't make muc

This sort of backward reasoning doesn't work very well. Yes, Dropbox solves a hard problem. Plenty of other people have solved hard problems and didn't make much money. You have to explore the factor that differentiates the cases if you want your post to have any real substance. The parent post would probably propose that this differentiating factor is, at least partially, luck.