Actually, playing games on Amazon, B & N, etc. with "reviews" by people who never read the book in question has been going on for at least a decade or two. I don't know who started it, but these days it's bilateral or multi-lateral. The only real effect is making the reviews of books on those sites useless. It's not AS bad on sites like Yelp, but something like a third of Yelp reviews are bogus - both good and bad reviews.