When I was teaching (it seems aeons ago!) I used to share with students the little conceit that photocopying was an alternative to reading. I proposed that some osmotic process meant that when a photocopy was put in a bag or a briefcase to be "read at home", something strange happened. Although the photocopy was never actually read, the information content leaked into the bag, and migrated through the handle up into one's brain.
The same thing may be happening with e-books: it is so easy to download all those books you feel you ought to have read, from the Gutenberg Project site. There they nestle (if that's what the zeros and ones can be thought of doing) in the memory of your iPad or e-readers and, because you know that they are immediately available for reading, you never actually read them. But you know them, because you've read about them. Somehow, also, there's an information leakage from the device into your brain and before long you find yourself deleting them because you no longer need to read them.