Publishers’ sales of consumer e-books grew 366% in 2011 according to the just-published Publishers’ Association Statistics Yearbook 2011. The Publishers Association, a trade organization serving book, journal and electronic publishers in the UK, reports all digital formats, including e-books, audio book downloads, and online subscriptions, accounted for 8% of the total invoiced sales of books in 2011, up from 5% in 2010. more