The story below reminds me of Handango, and I hope they won't go the same way.
Slashdot | Restauranteurs Say Yelp Uses Extortion To Ply Ad Sales:
"Readers Mike Van Pelt and EricThegreen point out a story in the East Bay Express alleging that online restaurant review site Yelp is doing more than providing a nice interface for foodies to share their impressions of restaurants. Instead, says the article, representatives from the site have called restaurants in the Bay area to solicit advertising, but with an interesting twist: the ad sales reps let restaurant owners know that, if they buy advertising at around $300 a month, Yelp can 'do something' about prominently displayed negative reviews of their restaurants. If the claims are true, it sure lowers my opinion of Yelp, which I'd thought of as one of the good guys (and a useful site). I wonder how many other online review sites might be doing something similar."