I guess there really is a market for everything. It would never have occured to me to sell reviews, or to buy reviews if I were a seller. Amazon is suing 1114 individual reviewers, as well it should. I rely, to some degree, on reviews when buying things.
I have perhaps a bad habit of never getting around to reviews, though sometimes if I am especially pleased, or vice-versa, I will. There are products you can’t review until you’ve used them a while. I recently bought an Android tablet that was well reviewed, seemed reasonable in quality, and had a higher price than three ill-fated tablets I’d ordered from Walmart. The cheaper ones disappointingly lasted only a few months, and were flaky in the meantime. I bought the seemingly better one to replace one of those. It lasted ten days. Technically, eight, since the date of the order is two days before we received it. The weakest point of all of them seems to be the screen. This one at least had wi-fi that worked reliably, plus it charged reliably and lasted well between charges. It breaking inspired a review. But I digress.
If I am going to look at reviews and average stars to help steer my buying (not that I haven’t bought things that had no rating at all yet), I want to know they are legitimate. I was dismayed enough that the company from which I bought my daughter a clarinet rewards a review with a second year of warranty.