Each time I'm buying more and more digital comic books. The sales on Comixology are very good and the "guided view" system that focus one panel at a time is very helpful (specially on smaller devies, like an iPhone).
And now companies like DC are publishing "digital-first" comics books, focusing mainly on digital platforms (even the art is formatted to fit a wide screen).
Of course I still buy physical editions, but the digital scheme seems more and more interesting to me.