If you actually do something you love it's a lot easier and takes on a lot more purpose.

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.

Building a mission and building a business go hand-in-hand. It is true that the primary thing that makes me excited about what we're doing is the mission, but I also think, from the very beginning, we've had this healthy understanding which is that we need to do both.

We are working hard to build a service that everyone, everywhere can use, whether they are a person, a company, a president or an organisation working for change

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

While we generally believe in free speech and giving everyone as much ability to speak as possible, in practice there are lots of barriers to that, whether it's legal restrictions, technological restrictions or you can't share what you want if you don't have access to the internet.

We're really at this point where we can take a step back and think about the next big things that we want to do.