Daniel Pink is a fabulous speaker and he's made it his business to understand the most recent research in human motivation. And what he's dug up is quite surprising for many people. When it comes to motivation, self-direction (autonomy) works best. Mastery, the urge to get better at something, is satisfying and important. And purpose, an opportunity to make a contribution (paid or not), plays a big role.
It's summed up beautifully in a brilliant talk that someone has taken the time to illustrate... and the illustrating matches the progression of his talk. It's fascinating to listen to and even more fascinating to watch.
I wrote about Dan Pink briefly in a previous post: Why Children Don't Like School. There's a link to Dan Pink's TED Talk from last summer, which is wonderful, too.