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

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.

In the olden times, privacy was good. Today people want to share, people are more open.

In a lot of ways Berlin is a symbol for me of Facebook's mission: bringing people together, connecting people and breaking down boundaries.

For the first time we're allowing developers who don't work at Facebook to develop applications just as if they were. That's a big deal because it means that all developers have a new way of doing business if they choose to take advantage of it. There are whole companies that are forming whose only product is a Facebook Platform application.

It's not because of the amount of money. For me and my colleagues, the most important thing is that we create an open information flow for people. Having media corporations owned by conglomerates is just not an attractive idea to me.

We have a pretty ambitious goal for the world. What we think will make the Web better. What we think will make all these businesses that integrate with us run more effectively. I think if we stay focused on doing that, that's really the main thing that we need to do.