According to Book Business Magazine, Bowker (the US ISBN agency) reports a 21-percent increase in self-published ISBNs—not titles—from 2014 to 2015: another indication of quickly rising interest in indie publishing. Beat Barblan, Bowker’s director of identifier services, clarifies that the company’s newly released figures show that in 2015, 727,125 ISBNs were applied to self-published works. That figure includes print and digital books combined.