Yeah.. I felt like Dropbox was easy to figure out how to make money (I.e. pay for storage). However, what seemed impossible was, "There's already x,y,z competit

Yeah.. I felt like Dropbox was easy to figure out how to make money (I.e. pay for storage). However, what seemed impossible was, "There's already x,y,z competitors in the field with years in advance..." And now, look at them :)