In that case, the reviewer seems to have completely misunderstood the subject of the review. That's a fine review (I guess) if the subject of the review is Amazon and the purchasing/delivery experience. Of course, it would be obvious from reading the review that it's not useful to somebody looking for book reviews and it should be (re)moved, but for whatever reason we have accepted platforms such as Amazon will simply fail to handle it properly.

i would hope by now such reviews are heavily down-weighted on the back end as far as contribution to the overall rating displayed for a given product. seems relatively easy to automatically detect and I struggle to see why Amazon would want deflated reviews for products they're selling.

maybe it's a legal thing, could be viewed as market place manipulation i suppose. and they've certainly had enough worries about anti-trust already.