The DRM dissuades me from buying books in advance. That's something I normally do at a bookstore since I don't go shopping that often, but often the mood for some of the books pass before I pick them up. That's fine by me with a paper book because I'll most likely get to it eventually. The mood will come around again. With DRM I have no guarantee for the future. Combine that with the ease and speed of acquiring content on a whim and my purchases are all based on what I want to read right now. The samples make it easy to put a book on my "to read" list when I hear of it without actually spending any money. I probably have 20 or 30 samples downloaded. So next time I need something new, there's quite a bit of variety waiting for me. I don't feel a need to pay for any book before I read the sample.
In that vein, I'm curious how the sampling may start to affect publishing if this kind of system takes off. If they have titles where they see a lot of samples downloaded compared to actual purchases that tells them something. I know many editors and writers strive to pull people into a book early on but I wonder if this sort of thing would make that even more important. I know marketing shapes much of the art we enjoy. I just get concerned the stronger the influence gets.