Customer reviews on Amazon are a mixed bag. For instance, movie reviews tend to be written by snobbish cineastes, technical geeks (all refresh rates and audio compression), slavish fanboys or people complaining that it took too long to get the DVD in the mail.
Others can be downright nasty and well, weird. (I once got into a fruitless exchange with a whacked out Christian fundie who took offense at, among other things, the supposed sexual liberties in The Third Man.) And some people seem to think the “useful/not useful” voting system is actually a choice between “agree/your [sic] a dumb fuck who just doesn’t get it”.
When Amazon first developed a visitor-generated review system it was a great idea—it created a community of sorts around their products, from people who actually purchased and used them. But now it has, with a few exceptions, become a bozos’ playground.
The only solution is to subvert from within. I wholeheartedly endorse mock reviews that usually take the form of complete idiocy or utter praise (or both). The joke is that there are always a handful of morons who think these are real reviews, and who often write flaming responses along the lines of, “your [sic] a dumb fuck who just doesn’t get it.”