The Association of American Publishers said Thursday that eBook sales for the month of January were up 115% from the same period last year. No surprise there, given that you can read them on most any mobile device these days, not just eReaders. Net sales of eBooks were $69.9 million during the month, up from $32.4 million in January 2010. On the other side of the coin, sales of paperback books were down 30% year-over-year, and sales of adult hardcover books dropped to $49.1 million in January 2011 from $55.4 million during January 2010. It doesn’t look like overpriced textbooks are going anywhere, as the higher education sector wasn’t hit as hard. Higher education sales were $382 million this January, down from $387.6 million reported in the same month in 2010.