The $399/yr doesn't make sense for a lot of people. It definitely is too high a price point for me as I only read 1 or 2 O'Reilly books a year at most. It's nice to have a copy lying around for reference years later.

On the flip side, I totally understand them going DRM-only for digital publishers. O'Reilly PDFs are way too easy to find for free with minimal Google-fu.