Early figures from The Association of American Publishers show that eBook sales have increased 115.8 percent for the first month of 2011 compared to January 2010, going from $32.4 million to $69.9 million. Downloadable Audio Books also jumped, though by a comparatively modest 8.8 percent ($6 million to $6.5 million).
The AAP was more concerned with the numbers than with explaining why sales skyrocketed the way they did, but if we had to guess, we'd say it's due to the eBook reader price war that erupted last year. Both Amazon (Kindle) and Barnes & Noble (Nook) slashed prices of their respective readers, while simultaneously pushing their mobile apps on a variety of platforms.
According to the AAP, total books sales on all platforms in all categories hit $805.7 million for January 2011, which is actually a slight decrease from January 2010 ($821.5 million). Sales of religious books grew by 5.6 percent, from $59.8 million to $52.6 million, while professional and scholarly eBooks grew by 1.3 percent, from $51.2 million to $51.8 million.