I think I've grown and learned a lot.

The question I ask myself like almost every day is: ‘Am I doing the most important thing I could be doing?' Unless I feel like I’m working on the most important problem that I can help with, then I’m not going to feel good about how I’m spending my time. And that’s what this company is.

I look at Google and think they have a strong academic culture. Elegant solutions to complex problems.

There are many machines throughout history that were built to do something better than a human can.

Advertising works most effectively when it's in line with what people are already trying to do. And people are trying to communicate in a certain way on Facebook - they share information with their friends, they learn about what their friends are doing - so there's really a whole new opportunity for a new type of advertising model within that.

Openness fundamentally affects a lot of the core institutions in society - the media, the economy, how people relate to the government and just their leadership.

It's tough to say, exactly, what things will look like in three to five years, but there's a lot of work to do in just moving along the path that we've already set out.