well, they should solve the chicken and egg problem of getting customers, tech problems are easy enough to solve, business problems are hard!
building your own social networking site that does everything facebook does and better is easy, get user's to sign up is not. trying to mine facebook for customers and data to jump start your site, well, that's not going to fly.
building your own social networking site that does everything facebook does and better is easy, get user's to sign up is not. trying to mine facebook for customers and data to jump start your site, well, that's not going to fly.