I almost don't have to add any commentary to this, because I also have cranky-faced opinions about Amazon, mostly revolving around their DRM and author-exclusivity contracts, neither of which are of any benefit to anyone except Amazon's attempts to become a publishing monopsony. Brooke Warner says:
For those of you who follow publishing news, or who are KDP authors, you know that on August 9, Amazon sent a very bizarre email to all of its KDP customers, which has been dissected best, in my opinion, here and here.
You can read the full email here, but this post is really about why I canceled my Amazon Prime account the next day.
Read her account and reasoning here: http://www.huffingtonpost.com/brooke-warner/why-i-canceled-my-amazon-_b_5690083.html