We started off by inviting our friends to use Quora, and then they invited their friends, and it just grew from there.

Our goal is to build this up as a knowledge base that anyone can look at. We're not just interested in people answering their friends' one-off questions.

The area we define as what Quora's good at is long-form text that's useful over time, and where you care about who wrote the text. Not that you need to be friends with them, just that they're someone trustworthy.

More than a billion people use the Internet, yet only a tiny fraction contribute their knowledge to it.

The stage is our pulpit, and you can use all of that energy and that music and the lights and the colors and the sound. But you know, you've got to be careful.

Anything you want to know, you go to Quora and get it. And at the same time, give people a platform that is easy to use for sharing the knowledge.