The only way it comes from an accelerator/incubator is if it built there, a-la Reddit from YC. Reddit is quickly becoming something that should fit the list at

The only way it comes from an accelerator/incubator is if it built there, a-la Reddit from YC. Reddit is quickly becoming something that should fit the list at the beginning of this post (it's blowing up) and it was built during YC's first class. However, the odds of say, Twitter, joining an incubator as they were blowing up seems unlikely.