In a new report on self-publishing, Bowker — the company that handles ISBNs (book identifier codes) and other bibliographic info for books published in the U.S. — says that the number of print and ebooks self-published annually is up by 287 percent since 2006 and now totals over 235,000 titles.

Bowker finds that 148,424 print books were self-published in 2011 — that means that 43 percent of all print books published in the U.S. in 2011 were self-published. 87,201 ebooks were self-published. Publishers Lunch notes a few important caveats: Bowker only counts titles with ISBNs, so “KDP exclusives and other sources that still don’t use ISBN numbers” aren’t included. That means the number of self-published ebooks is likely much higher than 87,201. In addition, the print and digital editions of a single title may be counted twice.

Bowker finds that four large companies dominate the self-publishing space. In 2011, Amazon’s CreateSpace was behind the creation of 58,412 titles, or 39 percent of all self-published print books.

Is anyone surprised by this?

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