Why Yelp Works - Bits - Technology - New York Times Blog

What Yelp did differently than these others, as Jeremy Stoppelman, the site’s co-founder and chief executive describes it, was to spend most of its energy attracting a small group of fanatic reviewers. It didn’t try to pay for reviews, as some sites have. It didn’t subordinate the users’ contributions to professional reviews, as on Citysearch, or to directory information, as on yellow-pages sites. Instead, it structured the site to motivate people through the praise and attention that their reviews receive from others. “Yelp is about the reviewing experience,” Mr. Stoppelman said. “It is like a blog with a little bit of structure.”