I think there's confusion around what the point of social networks is. A lot of different companies characterized as social networks have different goals - some serve the function of business networking, some are media portals. What we're trying to do is just make it really efficient for people to communicate, get information and share information.

It used to be the case, like, you'd switch jobs, and then maybe you wouldn't keep in touch with all the people that you knew from that old job. Just because it was too hard. But one of the things that Facebook does is it makes it really easy to just stay in touch with all these people.

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

Our goal is not to build a platform; it's to be cross all of them.

Of course the Silicon Valley is unique and Berlin is not yet comparable. But of all the different cities that are building a startup infrastructure, Berlin is the one with the most similar energy.

It only took me two weeks to build the first version of Facebook because I had so much stuff before then.

Critics worry that if we spend time paying attention to that new kind of media or technology instead of talking to each other that that is somehow isolating. But humans are fundamentally social. So I think in reality, if a technology doesn't actually help us socially understand each other better, it isn't going to catch on and succeed.