Facebook is uniquely positioned to answer questions that people have, like, what sushi restaurants have my friends gone to in New York lately and liked? These are queries you could potentially do with Facebook that you couldn't do with anything else, we just have to do it.

AI systems will enable doctors to diagnose diseases and treat people better, so blocking that progress is probably one of the worst things you can do for making the world better.

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

I updated my grilling app, iGrill, today and it now has Facebook integration that lets you see what other people are grilling right now around the world. Awesome.

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.

Berlin definitely has one of the most vibrant of the startup scenes that I have seen. Not really just across Europe, but across the whole world in terms of cities. It's an interesting dynamic.

There are a few other things that I built when I was at Harvard that were kind of smaller versions of Facebook. One such program was this program called Match. People could enter the different courses that they were taking, and see what other courses would be correlated with the courses they are taking.