You have to be very nimble and very open minded. Your success is going to be very dependent on how your adapt.

In the very beginning, Yelp started as a service where we really didn't think people would write reviews for fun. The whole concept of user-generated content was pretty nascent in 2004.

There is this cat and mouse game that plays out over time where our team comes up with new and interesting ideas to identify content that we shouldn't recommend, and over time people are constantly probing that, trying to figure out how can they get around that and get a better reputation on Yelp.

Maintaining the trust of the consumer is critical to our business

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.

I think with every successful consumer Internet business, there will be lawyers that are interested in going after your company, especially when they think that there's a financial incentive.

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