These people scam artists! Literally!
My wife and I own a small eco friendly artist collective and yelp sold us on a plan to bring 30 people in the door a day. Well we're lucky to get 30 people in a month none of which mention yelp even though our ad has a discount for just mentioning yelp. When I tried to cancel they told me I had to wait another 30 days before it would go into effect, costing me another $750 and then a breaking contract fee of an additional $750.
These people really suck, I wouldn't recommend them to my worst enemy. 0 stars.