A new analysis of ISBN data by Bowker found that the number of self-published books in 2012 rose 59% over 2011, growing to over 391,000 titles. The gain has been led by the increase in the output of e-books, although Bowker reported, print books still accounted for about 60% of self-published titles that carried an ISBN. In 2007, print books accounted for 89% of self-published titles.

The analysis also found that more than 80% of self-published titles "came to market with the support from just eight companies, including Smashwords and CreateSpace." Fiction is the most popular self-published genre followed by inspirational/spiritual works, books for children, and biographies.