I tried to buy my son a remote control car on Amazon a few weeks ago. I gave up after wading through 2 pages of 5 star reviewed products where the reviews all looked the same, all had the same structure. Many referenced "my 11 year old son", or the name of the company. This seems like something that can be weeded out using ML sentiment analysis. If too many reviews have the same structure, your posting gets demoted. If I could have found one legit looking review I would have bought that car, instead I gave up and went to The hobby store.