The major reason why Instagram works is that you can follow anyone out there and start following their photos immediately.
Kevin SystromEvery startup should address a real and demonstrated need in the world. If you build a solution to a problem lots of people have, it's so easy to sell your product to the world.
Kevin SystromInstagram was created because there was no single place dedicated to giving your mobile photos a place to live and to be seen.
Kevin Systrom