It is precisely because Hachette has been so successful in selling its ebooks through Amazon that it can’t afford to walk away from the retailer. By allowing Amazon to put a lock on its products whose key only Amazon possessed, Hachette has allowed Amazon to utterly usurp its relationship with its customers. The law of DRM means that neither the writer who created a book, nor the publisher who invested in it, gets to control its digital destiny: the lion’s share of copyright control goes to the ebook retailer whose sole contribution to the book was running it through a formatting script that locked it up with Amazon’s DRM.
The more books Hachette sold with Amazon DRM, the more its customers would have to give up to follow it to a competing store.
–Cory Doctorow on the DRM own goal.
DRM is promoted as locking a purchase to a customer. What it actually does is lock a customer to a retailer.