The BBC has also picked up the story.
http://www.bbc.co.uk/news/technology-17300074
The question I'd really like to see answered with hard numbers, is how much does the claim that the physical production is only a very small amount of the cost. But it also wasn't addressed that for physical books, I assume it's also mainly the only cost that is in perpetuity, since they don't have to pay editors and what not for subsequent costs, and I doubt they have a lot advertising costs associated with multiple printings down the line.