We help Chinese companies grow their customers abroad. They use Facebook ads to find more customers. For example, Lenovo used Facebook ads to sell its new phone. In China, I also see economic growth. We admire it.

Facebook is inherently viral. There are lots of sites that include a contact importer, and for lots of them it doesn't really make sense. For Facebook it fits so well. It wasn't until a few years in that we started building some tools that made it easier to import friends to the site. That was a huge thing that spiked growth.

I mean, we've built a lot of products that we think are good, and will help people share photos and share videos and write messages to each other. But it's really all about how people are spreading Facebook around the world in all these different countries. And that's what's so amazing about the scale that it's at today.

We think the fact that Instagram is connected to other services beyond Facebook is an important part of the experience...This is an important milestone for Facebook because it's the first time we've ever acquired a product and company with so many users.

Millions of people around the world love the Instagram app and the brand associated with it, and our goal is to help spread this app and brand to even more people.

When I'm introspective about the last few years I think the biggest mistake that we made, as a company, is betting too much on HTML5 as opposed to native... because it just wasn't there. And it's not that HTML5 is bad. I'm actually, on long-term, really excited about it. One of the things that's interesting is we actually have more people on a daily basis using mobile Web Facebook than we have using our iOS or Android apps combined. So mobile Web is a big thing for us.