Facebook is inherently viral. There are lots of sites that include a contact importer, and for lots of them it doesn't really make sense. For Facebook it fits so well. It wasn't until a few years in that we started building some tools that made it easier to import friends to the site. That was a huge thing that spiked growth.

I look at Google and think they have a strong academic culture. Elegant solutions to complex problems.

Nothing influences people more than are commendation from a trusted friend.

The thing I really care about is the mission, making the world open.

There have been misperceptions that we're trying to make all the information open on Facebook, and that's completely false. There are big buckets of information that we recommend that you share with only your friends privately. Then some of the more basic information, we recommend that that's visible to everyone.

We've changed our internal motto from "Move fast and break things" to "Move fast with stable infrastructure."

Helping a billion people connect is amazing, humbling and by far the thing I am most proud of in my life.