According to "BookStats, the Center for Publishing Market Data":
"eBooks are now fully embedded in the format infrastructure of Trade book publishing. The consistent growth of eBooks demonstrates that publishers have successfully evolved the technology environment for their content – more so than other historically print-based content industries. eBooks grew 45% since 2011 and now constitute 20% of the Trade market, playing an integral role in 2012 Trade revenue. The most pivotal driver of eBooks remains Adult Fiction, with Children’s/Young Adult also showing strong numbers" (http://bookstats.org/pdf/BookStats-Press-Release-2013-highlights.pdf, accessed 11-08-2013)
"BookStats, a Joint Venture between the Book Industry Study Group (BISG) and the Association of American Publishers (AAP), provided the most comprehensive available view of the size and shape of the US book publishing industry, measured by publisher net unit and dollar sales.
"This revolutionary data project carefully tracked transformational shifts in the sale of book content and provided US publisher net revenue and unit sales for 2008-2013 across three dimensions:
"METHODOLOGY
"Extrapolated data for BookStats was derived through a transparent methodology which fully sized the complete US publishing industry and provided the best means for understanding the ebook growth rate during a critical, transformative period.
"BookStats was a joint venture between the Book Industry Study Group (BISG) and the Association of American Publishers (AAP).
© 2014, the Association of American Publishers
© 2014, the Book Industry Study Group