Amazon.com reviews to be "helpful" over the last 3+ years. I started seriously reviewing books with Radia Perlman's Interconnections, 2nd Ed in May 2000. Since then I've written reviews of 116 books on security and computing topics. Some reviews of poor books caused quite a stir. Several were pulled only to have me resubmit "just the facts" in the form of direct quotes. Others caused me to argue with certain members of the community who praised books they should not have. Either they didn't read the book or they were too out of touch to realize printing 250 pages of C code did nothing to teach the reader about "hacking."
Every month I received many books to review. I only read those on my reading list or those that surprise me with their originality. I don't review books I've skimmed, unless the reason I've stopped reading was disappointment with content. As a result, many of my newer reviews are positive. Why waste time reading and reviewing a poor book? I don't get paid for reviews, but I do work on the side evaluating proposals and manuscripts.
I hope you find future reviews helpful!