Choose something you are passionate about - or a pain point that has affected you and that you feel really needs to be changed.

The biggest thing is to create a product that consumers find useful. As more and more people like something, it becomes harder and harder to have a conspiracy theory about it.

On mobile, what are the core apps? It's basically messaging, mapping and review data.

Consumers are empowered by Yelp and tools like it: before, when they had a bad experience, they didn't have much recourse. They could fume, but often nothing else other than tell their friends.

When Yelp first took off, our rankings on Google would fluctuate wildly.

There are so many businesses that are succeeding on Yelp that don't pay us a dollar, and we're really excited about that.

Yelp is in a very nice spot: local data, and especially review data, is one of the killer apps on mobile phones.