The amount of self-published book titles available in the marketplace went up 59% between 2011 and 2012, according to Bowker’s latest self-pubishing report. The report looked at U.S. ISBN data to identify that there were more than 391,000 books self-published in 2012. eBooks made up 40 percent of these ISBNs. The report examined how the self-publishing industry has grown over the past six years, illustrating a large proliferation of self-published titles in the marketplace. Amazon’s CreateSpace, Smashwords and Lulu.com led the list for putting out the most ISBNs of self-published works in the U.S. for both print & eBook from 2007-2012. For instance, CreateSpace’s output grew 3355.84% from 2007 to 2012. When broken out between print and eBooks, CreateSpace led with the highest volume for print books. Smashwords was the top player for eBooks.