From my DH-he doesn't read ebooks, but knows I am a fanatic.
"That groan you heard was from dozens of book publishers across the United States, reeling from yet another onslaught [iPad] against their bread and butter: the paper book. First it was Books on Tape, followed by books on phones, and then the king of business model killers, Amazon.com's Kindle."
http://hbswk.hbs.edu/item/6369.html
"Traditional trade book publishers are scared," says Harvard Business School professor Peter Olson. "The world that they have known, of print books and brick-and-mortar bookstores—the whole physical distribution system—is on the cusp of changing fundamentally."
Olson has a particularly informed view of the issue. Before arriving at HBS in 2008, he was CEO of Random House.