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.

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.

A lot of what Groupon is generating is demand for something people didn't know they wanted.

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.

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.