After years of selling digital comics on its own, publisher Dark Horse last week announced plans to sell single issues through (NASDAQ:AMZN) and its ComiXology subsidiary.

Dark Horse is best known for publishing independent titles with wide appeal. Among them are 300, Hellboy, The Mask, and Sin City, all of which have been adapted to the big screen in some form. In print, Dark Horse titles accounted for about 5% of overall sales to comics retailers in 2014.

The deal makes Amazon the heavy in single-issue digital comics distribution for all major publishers, a business that Comichron and ICv2 put at $100 million last year. That's 10.6% of the $935 million comic book market.

Yet it's a good bet none of this is helping Amazon to sell more Kindle readers.

Tablet trouble
To look at the numbers from Comichron and ICv2, you'd think the reverse would be true. Digital comics sales have quadrupled since 2011. In response, Marvel, DC and other publishers have introduced a whole series of digital-first titles and exclusives, some of which have been tied to popular movies and TV shows.

Netflix (NASDAQ:NFLX) is benefiting from precisely this sort of stunt right now. Creators Brian Michael Bendis and Michael Gaydos developed a 12-page digital exclusive preview to the forthcoming TV series Marvel's Jessica Jones, which begins streaming on Nov. 20 and is based on the comic book character of the same name. As of this writing, nearly 1,400 have rated the title at ComiXology.

So why isn't the Kindle benefiting when digital comics are becoming more popular every passing year? Competition is part of the problem. According to IDC, the worldwide tablet market declined in the second quarter and this time Amazon didn't rank among the top five suppliers like it did in Q4, when the e-tailer shipped an estimated 1.7 million units -- a near 70% drop year-over year. Too many of us like our iPads and Android tablets, it seems. 

How to buy comics when you're reading digitally
And yet Amazon isn't helping its case. Last May, the company altered the ComiXology software so that readers using iOS devices wouldn't be able to purchase new digital comics directly inside the app.

The thinking at the time seemed to be that users would be happy to either buy from a publisher's app and then connect the resulting file to a ComiXology reader, or buy directly on the Web and then access their books later. Users cried foul, rightly. And Kindle sales predictably went nowhere.

So, yes. Adding Dark Horse to ComiXology's digital inventory is a win. Crown Amazon the emerging king of digital comics, but let's stop short of building a throne. Thanks to the e-tailer's lagging position in the tablet market and earlier mistakes with in-app purchasing, this deal matters a lot less than it should have -- or could have.

What devices and software do you use to read digital comics? Will the Dark Horse deal have you buying from Amazon more often? Tell me on Twitter or reach out on Google Plus. I may use your comment in a follow-up article.