It all began when an author's book was pulled from Amazon without any warning. It took some time, and energy, but asking Amazon for help did produce results. And now we have a step-by-step guide if your book is ever in trouble on Amazon. The bottom line when using keywords - don't associate your book with a similar book or author. While it's been a common practice in publishing, along the lines of, if you like that book you'll like this one, Amazon's policies forbid the practice and now they're enforcing the rule.