Re: It's really simple
I'd observe that the much publicized spat between the publishers and Amazon was really a contest between an organization that understood the digital market (i.e. Amazon) and organizations that didn't (Hachette et al). We saw/see the same thing with the music publishers, the video producers, etc.
Yes, Amazon was trying it on. But the solution that they've adopted is counter-productive (as the data seems to show). A better solution would be to do what the physical retailers have done for years, which is come up with complex special arrangements (e.g. flat fee plus percentage, limited edition works, and so on ) so the retailer (WH Smiths, Amazon, whoever) can tinker with the formula without passing (all) of the risk upwards, but also with passing some of the profit that way.