According to a new analysis released in October by ProQuest affiliate Bowker, the ISBN agency, self-publishing continued its growth spurt, up 59 percent in 2012 over 2011, from 246,912 titles to 391,768. The gains were even more startling over the longer period for which Bowker collected data: a 422 percent rise since 2007. Not surprisingly, “ebooks continued to gain on print, comprising 40 percent of the ISBNs that were self-published in 2012 [156,837 vs. 234,931 for print], up from just 11 percent in 2011.”

A handful of companies dominated the list of self-publishers. “More than 80 percent of self-published titles came to market with support from just eight companies,” Bowker reported. They included Smashwords, CreateSpace, Lulu, AuthorHouse, Xlibris, and iUniverse. The last three are divisions of Author Solutions, owned by Penguin (now Penguin Random House).

The growth has made self-publishing services a big business. “The most successful self-publishers...invest in their business, hiring experts to fill skill gaps [like marketing], and that’s building a thriving new service infrastructure in publishing,” said Beat Barblan, Bowker director of identifier services. Bowker recently launched its own self-publishing service, SelfPublishedAuthor.com.

Bowker’s research also revealed the most popular self-publishing categories: most authors “plan to bring fiction to market, followed by inspirational or spiritual works, books for children, and biographies.” Categories for total publisher print output for 2012 (projected) based on ISBN counts were similar, with fiction in the lead, followed by juvenile, home economics, sociology/economics, and religion and science, which were tied.