Advertising works most effectively when it's in line with what people are already trying to do.

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.

I think I've grown and learned a lot.

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.

On engagement, we're already seeing that mobile users are more likely to be daily active users than desktop users. They're more likely to use Facebook six or seven days of the week.

Our strategy is very horizontal. We're trying to build a social layer for everything. Basically we're trying to make it so that every app everywhere can be social whether it's on the web, or mobile, or other devices.

I think as a company, if you can get two things right--having a clear direction on what you are trying to do and bringing in great people who can execute on the stuff--then you can do pretty well.