Carr's response to Sporkin:
I am the author of the original blog post. I'm not sure what exactly Ms. Sporkin read, but although she accuses me of "countless errors," she doesn't actually specify any of them. The AAP numbers on e-book sales growth that I used come from AAP reports on 1st quarter book sales from 2009 to 2013. Yes, they are current year vs. previous year numbers, which is precisely how I describe them in the text and chart. And yes, they are for the overall e-book market, which seems a reasonable way to illustrate overall trends in that market. I agree, of course, that examining segments of that market would also be useful. Nick Carr