Our role is to be a platform for making all of these apps more social, and it's kind of an extension of what we see happening on the web, with the exception of mobile, which I think will be even more important than the web in a few years - maybe even sooner.

When Facebook was getting started, no one used real identity - everything was anonymous or pseudonymous - and I thought that real identity should play a bigger part than it did.

We started off as this platform inside Facebook; and we were pretty clear from the beginning that that wasn't where it was going to end up. A lot of people saw it and asked, 'Why is Facebook trying to get all these applications inside Facebook when the web is clearly the platform?' And we actually agreed with that.

The days of you having a different image for your work friends or co-workers and for the other people you know are probably coming to an end pretty quickly. Having two identities for yourself is an example of a lack of integrity.

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. So inherently, our whole approach has to be a breadth-first approach rather than a depth-first one.

Back, you know, a few generations ago, people didn't have a way to share information and express their opinions efficiently to a lot of people. But now they do. Right now, with social networks and other tools on the Internet, all of these 500 million people have a way to say what they're thinking and have their voice be heard.