A couple of other obstacles:
– A book won’t become unreadable because of dead batteries. Want to read by candlelight during a weeklong blizzard – grab a paper book.
– Theft/breakage factor. If I lose a paperback at the beach, get sand in it, or have somene accidentally step on it, it’s not a major problem.
– Price. I’m not going to pay more for an eBook than the physical book, out of principle. The eBook is much cheaper to produce, and the cost savings should be passed on to the consumer.
Ironically, I sell eBooks of my own work, but that’s because it’s much cheaper to put out an eBook than a physical book.