Bill and Melinda Gates: Why giving away our wealth has been the most satisfying thing we've ever done

In 1993, Bill and Melinda Gates took a walk on the beach and made a big decision: to give their Microsoft wealth back to society. In conversation with Chris Anderson, the couple talks about their work at the Bill & Melinda Gates Foundation, as well as their marriage, their children, their failures and the satisfaction of giving most of their money away.