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.

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.

There are people who are really good managers, people who can manage a big organization, and then there are people who are very analytic or focused on strategy. Those two types don't usually tend to be in the same person. I would put myself much more in the latter camp.

At Facebook, we build tools to help people connect with the people they want and share what they want, and by doing this we are extending people's capacity to build and maintain relationships.

Almost any mistake you can make in running a company, I've probably made

If we want to have the biggest impact, the best way to do this is to make sure we always focus on solving the most important problems.

Find that thing you are super passionate about. A lot of founding principles of Facebook are that if people have access to more information and are more connected, it will make the world better; people will have more understanding, more empathy. That’s the guiding principle for me. On hard days, I really just step back, and that’s the thing that keeps me going.