DC Comics has just made their periodical comics available in digital form on the Kindle Store, iBookstore and NOOK Store, becoming the first major comics publisher to make their weekly releases available on every major digital platform. The books went on sale Tuesday.

DC’s periodical comics will continue to be available through ComiXology as well as the DC and Vertigo stand-alone apps. DC’s collected editions and graphic novels, such as Watchmen, were already available on all platforms, as well as ComiXology.

According to DC senior v-p of digital Hank Kanalz, the program is rolling out with about 70 different titles, and more will be added, including back issues, as the program expands. “It took a long time to make today happen," he said of the deal which involved, Apple, Amazon and Barnes & Noble.

DC's digital comics program already has grown notably since introducing day-and-date releases a year ago. According to figures released by DC, overall digital comic sales are up 197% over 2011 through September. During the same period, print sales are up 12%, bucking the trend in other media for brick-and mortar-decline as digital increases. That increase includes last year’s record-setting New 52 launch. “Even against those strong numbers we are up double digits in 2012,” said a DC spokesperson.

Day and date releases will continue to be at the same price as print, before dropping to $1.99 a month after release. (An early release showed at least one DC comic getting a standard Nook discount, but those glitches have now been fixed.)

“As e-readers and tablets continue to explode in popularity it’s important for us to offer consumers convenience and choice in how they download digital comics and graphic novels and these new distribution deals with the top three e-bookstores do just that,” said Jim Lee, co-publisher, DC Entertainment in a statement.

Although the digital comics will not be available via Comixology’s app for Kindle, Kanalz still sees the move as additive. “The whole point is for readers to be able to choose their platform. We know there are many devoted Kindle and Nook folks who want to build their library within the different platforms.”

Indeed, for consumers there’s quite a bit of choice involved: each platform offers its own iteration of technology to fit full-sized comics pages on smaller devices, and all work in different ways, with the iBookstore offers the traditional epub format.

Although there’s been talk of beginning to sell subscriptions to digital comics, Kanalz say this isn’t being offered yet, “But we look at everything.”

Most books sell in digital format in similar proportions to print, says Kanalz, although digital sales surge when there is media attention for a title, such as the recent kiss between Superman and Wonder Woman, or Clark Kent's decision to quit the Daily Planet. "It's not a surprise, but you see the spike in the news and then everyone flocks to digital to get the issue that sells out in print." Hits sell whatever the format—the current Batman storyline, "Death in the Family" by writer Scott Snyder is "off the charts" in digital format.