Diamond Digital has released a video for retailers that explains how to use its program. Retailers have two ways of selling digitally through Diamond: They can print out digital codes that they sell and the user then redeems for a digital comic, and they can also set up a digital comics storefront and keep a cut of the sales. The video does a nice job of explaining how to do that. And for the rest of us, it's a peek behind the digital curtain.

One revealing detail is that retailers keep 33 percent of the cover price of any comic sold digitally. It's safe to say that's less than they would make from the sale of a printed comic, but they don't have to worry about ordering inventory or ending up with unsold comics on their hands. On the other hand, it's more than they would get from comiXology, which has a similar program; comiXology gives retailers 15 percent of the sale price if they use a standard comiXology storefront and 30 percent if they use the DC storefront. (On the other hand, comiXology offers a wider range of comics for sale, so there you go. Nothing's perfect.) Retailers take in the full amount for each sale, then Diamond bills them for 67 percent on their weekly invoice.

Customers can redeem the codes at the website digitalcomicsreader.com or on a special Digital Comics Reader app, which is available for Android and iPhone.