And I think the only buy one only works if your razors will only use your blades. In the book market, you are quickly finding that there is significant resistance to this paradigm, just as it was in music. If the information isn't free, people at least want it to be semi-open. And if not semi-open, then able to use open standards. I frequent a nook site, and one of the big driving factors that is causing people (including me) to look at the iPad, even if it is the inferior reading device is the fact that it resists lock in. iBooks doesn't, for sure, but there is Stanza (a completely open reader), Kindle for iPad, BN eReader for iPad, and now the Borders eReader for iPad. So no matter what the publisher war results in, you're still able to read whatever book you want. Not an ideal situation, but it's better than not being able to read a book because the device you're using couldn't get a license. A recent example of this is the book Changes by Jim Butcher (in the Dresden Files series- highly recommended). The only outlet for purchasing the digital copy was Barnes and Noble. So a friend with a Kindle had to get the dead tree edition. I personally use my iPhone currently to read, so I was able to download it for the B&N eReader and read it.
TL;DR version- DRM sucks. But if you have to have it, I'm not going to let my purchasing of hardware and your sucky DRM keep me from getting a book I want to read.