Gee. Not long to go before resources will be better spent watching the people who aren't on the list.

I never much took to Schelling/Gladwell's 'tipping point' idea. It's too pat, and smacks of post hoc data rationalization. It's just as easy to find major memes of all kinds that can't be ascribed to the tipping point model (as a number of people have demonstrated here).

Certainly there is some kind of crucial nexus that is often needed for an idea to propagate rapidly but not all major changes happen fast, nor dramatically. Success does not depend on speed.