Altruism is one of the most fundamentally social impulses, and doing things for others without expecting anything in return is core to what makes us human. This is why, from the day Facebook Platform launched in 2007, Causes has been honored to be one of the most popular applications, with over 140 million users.

The zone is a place that you rarely visit. It's not some place you go every week. The zone is sacred ground.

Even when I was playing, I never thought much about the individual honors. I wanted to go to the Super Bowl.

Whatever you think of Facebook, you cannot fault it for lack of ambition.

Grassroots organizing tends to be most available to big campaigns, but it's actually most useful to small ones. You can't win a presidential campaign without going on TV, but you can win a local election simply by organizing your community. NationBuilder levels the playing field.

For a football coach, there's nothing that matches the pain of a team not playing up to its capabilities.

People can care about changing the world. But what gets them to act is pressure and social reward.