they should give more weight to the "verified purchase" reviews, I might even go as far as to say disallow reviews unless you actually bought the product, it would stop a lot of this, and the stupid review bandwagon that people seem to jump on
Yes it still means a person can buy the book, then give it a bad review, then return it, however the effort to do this would be higher AND there would be a purchase pattern that begins to show itself.
When the purchase price is so low, astroturfing with "verified purchase" reviews looks to be quite feasible.
I've never published a dishonest review, but I have reviewed a product or two that I bought somewhere else (not on Amazon), but I certainly "bought the product."