There is no relationship between the sales calls and the filtering algorithm. That is what the dismissed class action lawsuit was about. All "evidence" people h

There is no relationship between the sales calls and the filtering algorithm. That is what the dismissed class action lawsuit was about. All "evidence" people have is purely anecdotal. Verifying a "business" relationship may work but it still won't solve all of the problems. You can still pay people to show up at your restaurant, pay with their credit card and write a five star review. You can still pay people to show up at a competitors restaurant, pay with their credit card and write a one star review. It simply increases the cost of the spam (which is a good thing). They should probably create a way to do this but it won't solve the fundamental problem: the reviewer pool is an unreliable source of information. "X people found that review helpful" A helpful review is not the same as an accurate review based on experience. I would find a well written review helpful. However, the review could still be inaccurate or fake just well written. This is simply another data point for spam detection and one with many confounders at that. One has to simply google around about the state of Amazon reviews to see the flaws in this approach. Once again. I stand by my assertion, detecting spam reviews is extremely difficult because it is a human problem.