If that correlation existed, it wouldn't still indicate causation, i.e. that advertising causes the filter bias to change. Maybe the companies who eschew planting fake reviews are also the ones who are willing to pay for advertising.
Yelp has repeatedly, strenuously denied the extortion claims, yet the accusations continue to come. I think a phone recording by one of these accusers would be an excellent smoking gun. Or if someone here calls on behalf of a restaurant or other business (that they have a stake in and has filtered reviews), they could report back to us on what happened. In the meantime, I'm inclined to apply the "innocent until proven guilty" principle in favor of Yelp.
Very true! Thanks for gently pointing out that hole in my logic. The leap from correlation to causation is a very big one. Anyhow, like you, until I see something other than restaurateurs complaining, I'll give Yelp the benefit of the doubt here.
Yelp has repeatedly, strenuously denied the extortion claims, yet the accusations continue to come. I think a phone recording by one of these accusers would be an excellent smoking gun. Or if someone here calls on behalf of a restaurant or other business (that they have a stake in and has filtered reviews), they could report back to us on what happened. In the meantime, I'm inclined to apply the "innocent until proven guilty" principle in favor of Yelp.