One of the purposes of life, and selfishly what makes people happy, is building things that are impactful.

The first time I looked at Yammer, I thought I was on Facebook. Work is not a social network, with serendipitous communications and photo collections. Work is about managing tasks and responding to things quickly.

Mindfulness has helped me succeed in almost every dimension of my life. By stopping regularly to look inward and become aware of my mental state, I stay connected to the source of my actions and thoughts and can guide them with considerably more intention.

As with Google, Facebook was a place that just concentrated a lot of top talent. It's just sort of natural that those people would go on and continue to be successful.

There's a lot of complacency in philanthropy. People figure organizations are trying to do good, and that's enough, even if the results aren't there. But that's wasteful and inefficient. It crowds out better programs.

Once a few Facebook employees put together a promising idea and start a company, that's very exciting to people. I happen to think being a Facebook employee is really correlated with good ideas.