The AAP put out a press release today with the reported sales figures for the USA book market. Note that this isn't the complete data on the market, just what was reported to the AAP. Here is what the press release said about ebooks:
E-book sales jumped up 184.8 percent for the month ($28.5 million), reflecting an increase of 251.9 percent for the year.
I'm not sure this is news anymore. It used to be a surprise when ebooks posted this kind of sales increase. But we've seen this now for just about every month for the last 2 years. Yippee.
BTW, this isn't the actual total sales, just the ones reported to the AAP. Not all publishers are members, nor do they all report in a timely manner.