Amazon removes my review of Dan's book

Last week I reviewed Dan Gillmor's We the Media for Mindjack, and uploaded the same review to the We the Media page on Amazon.com.

It was immediately taken down. Today I received an email explanation about why it was removed:

Your review of "We the Media" was removed because your comments in large part focused on your personal opinions of the subject matter, rather than reviewing the title itself.

While we appreciate your opinions on the subject, the intent of customer reviews is to assist our customers in making an informed purchase decision. We provide our customer reviews section for you to comment on the merits of the book and the author's writing style. We ask that you not use it as a place for discourse on the subject matter.

Wow.

So instead of an informed review that places the contents of the book in context, they'd rather have ramblings such as: "I looked up what the author had to say about chat rooms, Yahoo!, free speech, etc. and was always amazed to find merely a sequence of vacuous ramblings offering nothing new. I find it even difficult to write a critical review because there is almost nothing to here to criticize."