Right now, they do. But as digital substitutes get better, the physical market is going to shrink. Books and comics are just data, there is no reason they won't

Right now, they do. But as digital substitutes get better, the physical market is going to shrink. Books and comics are just data, there is no reason they won't go the same way as music and movies, by which I mean, better and easier to deal with in digital form than in the physical. Honestly, beyond that little truth, I don't think that it makes too much sense to draw lots of parallels between these industries. Use patterns for books movies and music are very different, as are their creation. Each industry is going to have to sort out on it's own how to deal with the brave new future.