Unfortunately Yelp has defeated a class action lawsuit brought against them in California. The evidence is clear that they are blackmailing small business, it just doesn’t meet the legal standard. These are smart people. We can only hope the public is aware of what Yelp is doing. In the Bay Area they are in general. There was a report on this blog earlier that suggested customers are at least skeptical about review sites. That said if you have 5, 1 star reviews because you are too expensive, or you repairs don’t last, you do have a problem.
Article about Yelp lawsuit http://www.forbes.com/sites/ericgoldman/2013/02/06/yelp-defeats-legal-challenge-to-its-user-review-filter/