They're not doing either. I worked there, on the systems in question.

This just is not true. I have worked with a number of companies that have tried to pay Yelp to unhide their legitimate, positive reviews and there was nothing Yelp would do about it, no matter what proof you offered of the transaction or customer relationship.

Their algorithm rules all, sales has zero say in it.

If you’re so inclined, you can look up your local Denny’s for proof of the opposite. They are a big time advertiser with pretty poor reviews on average.