Comics and graphic novels are the latest publishing category to show a drop in digital sales. The pop culture trade news site ICv2 has reported that North American digital comics sales in 2015 were $90 million, a 10% decline from the $100 million in sales reported the year before.

The drop in digital comics sales comes after six consecutive years of annual growth in the category. It also mirrors a similar decline in the sales of prose e-books, cited by Association of American Publishers statistics. The ICv2 figures do not include subscription "all you can read" services such as Crunchyroll, Marvel Unlimited, Scribd Comics, Comixology Unlimited and Comic Blitz.

Milton Griepp, ICv2 CEO, said many comics industry observers are blaming the decline in sales on a saturated market for digital devices. He noted that the report cites a slowdown in purchases of new devices, as well as a decline in the number of new comics consumers looking for digital comics content.

“Catalogue purchases of digital comics are less robust, as longer-term digital consumers have already acquired much of the backlist that they want in their libraries,” the report said.

Despite the drop, ICv2's report pointed out at last year's New York Comic Con that the comics market as a whole is growing. The report emphasized that digital comics continue to broaden the types of consumers in the comics marketplace and are, in particular, attracting more female consumers to the the category. Also at last year's New York Comic Con, digital comics marketplace Comixology reported that 30% of its new customers are female, up from 20% two years ago.

Digital comics are also credited with increasing the kinds of comics available in the marketplace, adding manga and Euro-comics. They have been instrumental in expanding the selection options in the U.S. marketplace, which has been dominated historically by the superhero genre.