''Although adding photo filters to Twitter may seem like a trivial addition to a social network that processes nearly a billion 140-character missives every two days, it could prove to be an important part of the company’s business.'' NY Times Blog
Well, it is not only about having THAT idea. In my opinion, it is the execution and integration of right elements. You do not have to go far for such examples. I remember a web based photo editing app called Picnik which was eventually bought by Google as a new editing tool for Google+. Unfortunately it never really caught on and left many loyal Picnik users angry.
