Yelp is already comped.
Your listing goes to the top when you pay their extortion fees.
It's like every other rating service on the internet - they are 100% comped and you can buy your way to the top slot on any of them.
Angies List is a YUGE rapist operation - skimming and not even delivering when you pay them for your spot.
You think Google doesn't control it's own algo? You think SEO really works?
Wake up people - if they are peddling trust to you, then they are already comped or they would not need to be peddling it in the first place….