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.

If you don't risk anything you risk everything

I hope that Facebook and other Internet technologies were able to help people, just like we hope that we help them communicate and organize and do whatever they want to every single day, but I don't pretend that if Facebook didn't exist, that this wouldn't even be possible. Of course, it would have.

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.

In addition to building better products, a more open world will also encourage businesses to engage with their customers directly and authentically. More than four million businesses have Pages on Facebook that they use to have a dialogue with their customers. We expect this trend to grow as well.

If you think about companies that were built in Silicon Valley, a lot of them early on were chip companies. And now the companies that are there, like Apple, are much more successful than any of the chip companies were.

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