While Yelp has gathered a marvelous collection of business reviews, their app hides reviews of their own Yelp business. Why? Maybe its because most of them are from pissed-off advertisers like myself. I tried their pay-per-click scheme, which cost me hundreds of dollars, and brought me ZERO paying customers. Yelp refused to honor the $400 credit that my Yelp sales rep offered to get me to try Yelp advertising in the first place.
If a Yelp salesman entices you with: "Don't you think if somebody clicks on your ad, that they will probably buy your service?" -- Remember my testimony and tell them, "I would be a fool to think that."