More than four million businesses have Pages on Facebook that they use to have a dialogue with their customers.

The unsupervised learning is the way most people will learn in the future. You have this model of how the world works in your head and you're refining it to predict what you think is going to happen in the future.

When you want to change things, you can't please everyone. If you do please everyone, you aren't making enough progress.

The world isn't set up equally, and the first billion people using Facebook have way more money than the rest of the world combined.

We look for people who are passionate about something. In a way, it almost doesn’t matter what you’re passionate about. What we really look for when we’re interviewing people is what they’ve shown an initiative to do on their own.

Advertising works most effectively when it's in line with what people are already trying to do. And people are trying to communicate in a certain way on Facebook - they share information with their friends, they learn about what their friends are doing - so there's really a whole new opportunity for a new type of advertising model within that.

Every application will be designed from the ground up to use real identity and friends.