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.

On Quora, you're not answering questions because you want to get points or because you have nothing else to do.

A lot of people really like to answer questions, and they really enjoy sharing their knowledge. Especially people who have valuable knowledge.

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

The Internet was supposed to allow anyone to set up a web page and share their knowledge with the world. But in practice, it's too difficult and takes too long, and almost no one does it.

Blogs are easy to start, but unless the author is famous, it takes years to build a following.