In early 2008, it was confirmed that there would be an opportunity to build applications for the iPhone. We were fortunate enough to make the right call on that: to bet early, to put resources into it and have a pretty good application in the store at the moment when it opened.

The entrepreneurs that really make it are the ones that start with an idea but are ready to change it at a moment's notice.

Maintaining the trust of the consumer is critical to our business. We live and breathe only one thing, which is wanting to connect consumers with great local businesses, and I don't feel we can do that if we don't have effective ways to prevent gaming of the system.

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

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

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

Maintaining the trust of the consumer is critical to our business