I wouldn't give Yelp too much praise. It's been alleged that Yelp engages in astroturfing and unfair business practices[0], and the documentary "Billion Dollar Bully"[1] even accuses them of "Mob-Like Behavior".
[0] https://en.wikipedia.org/wiki/Yelp [1] https://en.wikipedia.org/wiki/Billion_Dollar_Bully