Those reviews certainly seem pretty sketchy, and this sort of issue is definitely not unique to books. What would be Amazon's best possible approach to dealing with this? Does there exist software good enough at distinguishing potentially fake reviews from real ones?
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
When the purchase price is so low, astroturfing with "verified purchase" reviews looks to be quite feasible.