We see reports on ebook sales everywhere that don't include self - published authors, who might possibly account for 25 % or more of total ebook sales. (hughhowey.com)
Overall in 2011, the company experienced 134 % growth over total ebook sales in 2010. (goodereader.com)
Total eBook sales rose 30 % in the quarter and accounted for 22 % of revenue in the most recent period compared to 15 % in the first quarter of fiscal 2013. (goodereader.com)