If the original Facebook was the first five minutes [of a conversation] and the stream was the next 15, what I want to show you today is the rest-the next few hours of a deep engaging conversation.

We want Facebook to be one of the best places people can go to learn how to build stuff.

Stuff like photos and events and groups - we've built pretty basic versions of those apps to start but they ended up being so much more used because of their social integrations.

I personally don't invest in a lot of companies because I think it would be a conflict of interest and Facebook doesn't typically either.

Look at the way celebrities and politicians are using Facebook already. When Ashton Kutcher posts a video, he gets hundreds of pieces of feedback. Maybe he doesn't have time to read them all or respond to them all, but he's getting good feedback and getting a good sense of how people are thinking about that and maybe can respond to some of it.

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 think a simple rule of business is, if you do the things that are easier first, then you can actually make a lot of progress.