I think that people just have this core desire to express who they are. And I think that's always existed.

There are a few other things that I built when I was at Harvard that were kind of smaller versions of Facebook.

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.

So many businesses get worried about looking like they might make a mistake, they become afraid to take any risk. Companies are set up so that people judge each other on failure. I am not going to get fired if we have a bad year. Or a bad five years. I don’t have to worry about making things look good if they’re not. I can actually set up the company to create value.

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.

Some of the best ideas throughout the company's evolution have been from places all throughout the company whether it's an engineer or someone on the customer support team. Just different areas around the company.

Building a mission and building a business go hand-in-hand. It is true that the primary thing that makes me excited about what we're doing is the mission, but I also think, from the very beginning, we've had this healthy understanding which is that we need to do both.