Apparently Amazon is warning publishers that they mustn't discount on their websites. Or if the publisher dares to continue Amazon will take the selling price as the RRP and apply its terms of trading to that price. In other words, if Amazon receives a 50% discount from Penguin, for example, but Penguin is selling a £20 book for £15 on its website, Amazon will only give Penguin £7.50, rather than £10.
If you think that perhaps I have dreamed this nonsense while in a drunken stupor, please read this article for the full SP. This is on top of the previous nonsense of wanting to print all US POD books on its own presses.
It is going to hurt me, because I like cheap books, and I enjoy the convenience of being able to order practically any book I want from the same place. But I am going to boycott these bullying oiks, and I would encourage everyone to do the same. Amazon is not the only source for books, and needs to be reminded of this fact. Go to some trouble, spend a little more money if you have to. You're worth it!