I think its popular because 10,000 hours seems nicely out of reach for most people, so it lets you off the hook for not being good at stuff. It's not my fault I can't play the piano: my lifestyle precludes it. If only I didn't have a job/kids/whatever, then people could see how creative I really am. Gladwell allows one to continue doing nothing while still imagining oneself as a thwarted hero. A great deal for just $16.99.