Yelp business reviews are massaged by their so called "fraud detection algorithm". A business is black-mailed into paying Yelp for good reviews. The "algorithm" simply does not let good reviews get posted until you pay Yelp for them. Many companies have taken Yelp to court, but Yelp hides behind their secret algorithms' patent.
Yelp, like the Better Business Bureau, gets their money from donating business. Who are they really working for? Just follow the money.