Why Publishers Must Go Mobile
In its annual summary of ISBNs registered for self-published works, Bowker reported that nearly 730,000 were issued in 2015, up from 153,000 in 2010. The numbers cover ISBNs issued for both print and digital formats.
The ISBN is a useful way to monitor sales across the supply chain, but works published on a single platform can forgo the identifier and rely on platforms such as Amazon to report performance. Because the creators of many self-published works do not apply for ISBNs, the number of new works published each year is believed to be greater than Bowker is able to report.