Convince me it's extortion and I might agree with you, but I've read many filtered and unfiltered reviews and it seems that Yelp does a fine job filtering. The filtered reviews sound like morons or shills; the unfiltered reviews sound like customers sharing an experience. Paying Yelp to advertise doesn't seem to be a factor.

I'm just not feeling the hate. My main problem with Yelp is that the star ratings are useless because everyone else's standards are different from mine. I don't care if something is expensive; I'm happy to pay money for good food and good service. But for other people, that's an automatic negative eight billion star rating. So Yelp becomes essentially useless unless I read every review. (I understand Zagat has controls for this, but I've never actually used it.)

And now for the statement that's going to get me in trouble: whenever I see an ad like a Yelp ad or an Adsense ad, it implies a certain amount of shadiness to me. The businesses that are good don't need to buy ads, leaving most ads to be from businesses with some problem.