Article:
How Sustainable is the Kindle’s Early Success?
http://www.moneymorning.com/2009/10/13/amazon-kindle/
Here's a quote from it that I found interesting, and I wonder how reliable their info is (emphasis is mine):
"Even though e-books are heavily discounted compared to their hardback equivalents, they are wildly profitable – costing Amazon just $1.50 per book, Credit Suisse Group AG (NYSE ADR: CS) analysts estimate. And that margin is expected to improve as Amazon’s costs come down by 2012, when its profit on e-book sales alone will soar to $31 million."