Over at Xconomy there is a write about the Comixology model:
Then the iPhone was born—and Comixology was forced to speed up its plans. “We thought we’d have a couple of years to get to digital comic books, but the minute Apple put up the app store, there were people out there putting out some form of digital comics,†Steinberger says. Apple soon began allowing in-app purchases—an opportunity, Steinberger says to create a major revenue stream for Comixology.
But Steinberger wanted to ensure that the experience of reading comics digitally would be just as satisfying for fans as leafing through comic books is. So he and his software developers came up with “guided view,†a system that allows readers to see the entire page as the artist originally designed it, while easily swiping from one text bubble to the next so they can page through the story sequentially.
Worth a read due to the different viewpoint on digital comics!