There's also a sizeable fraction of the reading public of all ages who still prefer print books for a host of reasons both sentimental and practical. (The one I've just discovered: I can't read ebooks before bed because the blue light from the iPad screen keeps me up. Whoops.)

Ebooks have mostly killed the mass-market paperback, though---more's the pity for beach-reading and other circumstances where I don't want to have to worry about the physical condition of sensitive electronics.