The number of self-published books topped the 1 million mark for the first time in 2017, according to Bowker’s annual report on the number of ISBNs that were issued to self-published authors. The total number of ISBNs issued last year rose 28% over 2016, to 1,009,188.
The gain was due entirely to the increase in the number of print ISBNs issued by Bowker last year—879,587, a jump of 38% over 2016. The number of ISBNs issued for e-books released by self-published authors fell 13% from 2016, to 129,601.
While Bowker noted that the 2017 decline is the third consecutive year the number of ISBNs issued for e-books fell, the drop is more likely due to authors moving to Amazon’s KDP self-publishing platform than an overall decline in the number e-books that were self-published last year. Bowker’s e-book numbers are based on ISBNs issued, and since KDP uses Amazon’s own ASIN identifiers, KDP’s titles do not appear in the Bowker data. Amazon does not disclose the number of KDP titles that it releases annually.
Bowker does, however, capture the number of print books produced by Amazon’s CreateSpace division, and the figures show a 50% increase in title output in 2017, with the number of self-published books released by the company reaching nearly 752,000. CreateSpace’s closest competitor in the print space, Lulu, saw units fall 5%, to 36,651.
The number of print ISBNs issued by the various imprints of Authors Solutions fell again in 2017, dropping 19%, to 15,667. The number of print ISBNs issued annually by Author Solutions has fallen every year since 2012, when the company had 31,531 print self-published titles.
Absent numbers from Amazon, Smashwords had the highest number of e-book titles last year, although the number fell 15%, to 74,290. Lulu was in second place with 30,747 ISBNs, down 3% from 2016. Author Solutions had 10,203 e-book titles last year, down 6% from 2016
The total 28% gain in self-published books last year was a marked improvement over the 8% increase in self-published titles released in 2016 compared to 2015. Last year, Bowker’s director of identifier services Beat Barblan suggested that the 8% gain showed that the self-publishing market may be maturing, but the much higher increase in 2017 prompted Barblan to comment that the growth in self-publishing “shows no signs of slowing down.”