It seems that Amazon is falsifying search results to exclude "adult" material - by which they apparently mean books which present a positive image of gay, lesbian, transexual and bisexual life. See for instance the Twitter #amazonfail and this post at SmartBitchesTrashyBooks -
http://www.smartbitchestrashybooks.com/index.php.
To which the power of the people says "Amazon Rank" by clicking on the following link, so that Google searches for "Amazon Rank" will come up with a result that shows that in this Amazon is most decidedly rank -
http://www.smartbitchestrashybooks.com/amazonrank