So in answer to Nate Hoffelder’s question on Twitter about the percentage of ISBNs assigned to ebooks…Roy Crego from Bowker (who is totally my go-to genius for number crunching there) reports the following:
There were a total of 1,555,790 ISBNs assigned to book products (ebooks, audiobooks, print books, and some video) in 2011 (that Bowker knows of – not all publishers report back to Bowker what they assign).
Of those, 183,183 were assigned to ebooks. Which is 11.77%.
The caution here is that POD titles take up the bulk of ISBN assignments. And thanks to Lulu, Bibliolife, and other services, there are tons of POD titles published per year. How many of them ever actually get printed and sold?
UPDATED TO ADD: Roy says he derived these numbers from Books in Print.