Ebook - Wikipedia In 2013, around 2.5% of all trade titles sold were in digital format. This was a 400% growth over 2012 when only 0.5% of trade titles were digital. In 2014, the growth was slower, and Brazil had 3.5% of its trade titles being sold as e-books. China. The Wischenbart Report 2015 estimates the e-book market share to be around 1%. Public domain books. Public domain books are those …