I have a view that if you build something that's good, and you keep making it better, it lasts.

Lawyers and other professionals are using Quora to build their reputation and build their bonafides.

If you imagine your friend is recommending you content on a topic they're an expert on, they can do a really good job of that. They know what you're interested in, they know your personality, they know if you have a scientific type of mind-set or not.

When companies get big, they slow down. They're not as exciting. If you want to get something done, it takes a lot of time and a lot of meetings.

Most of the stuff that people look at on Quora today was not written in the last month. You write something really good, and maybe it's the definitive answer on the Internet for the next 10 years. Maybe it's only a year, but not like a tweet, where it's only relevant for a day or a week.

When you look at Yahoo Answers, there can be a lot of garbage. But if you're careful about the rules and supporting good contributions, over time you can get better and better, like Wikipedia.