In a way, I'm sorry to contribute to the slow decline of the brick-and-morter book store, but mainly I'm furious at Barnes & Noble, and I'm going to stop patronizing them. The entire reason is DRM.
When B&N first started putting DRM into books, it was tedious but easy to circumvent. Because, as we all know, DRM is fundamentally flawed, stupid, and poorly implemented by idiots who should be embarrassed to call themselves programmers. So I limped along because I like the Nook hardware and the integration with the book store. Recently, though, I had an experience with some books that made using the books more painful, and it became more frustrating and less of a convenience.
Here's a chat transcript with the B&N rep: