I didn't say that it did, only that it's completely legal for them to do it and for them to do it secretly.
I have firsthand experience with them biasing ratings from helping friends manage Yelp listings. I don't know how widespread it is, but it does happen. While possible, it seems unlikely that thousands of people have reported the same pattern (good reviews buried after declining to become a Yelp customer).
You can see this yourself on many listings. Click on the reviews that Yelp has hidden because of "quality issues". That's what they use for plausible deniability. My own positive reviews have been hidden from businesses (no personal connection to them, just places I liked) for being "suspicious".
A lot of those folks that are hidden have 0 connections or linked accounts, few reviews, and/or all reviews being the same star rating. I’m not saying it’s a good system but I see a variety of ratings hidden in that section.
All of my wife’s reviews were being hidden until she added established accounts as friends on yelp. Not sure why anyone treats it as a social network but so it goes.
