Don't know if this is true, but according to the publisher, "the plan would allow Amazon to make more money selling Macmillan books and that Macmillan would make less." This sounds, to me, altogether too believable. Full article is here:
Another sobering point made in the article is that, according to Amazon, "The company now sells six digital copies to every 10 physical ones of books available in either format."
And here's an interesting batch of comments on the issue from boingboing.net, a tech-oriented web site. (DRM, by the way, stands for Digital Rights Management, which is essentially electronic copyright, but is also apparently a mechanism by which Amazon can delete books that readers have bought, paid for, and downloaded.)
The times, they are a-changin'.