I'm going to be honest, as a college kid during the iTunes age, I never saw a real dent in piracy because iTunes was around. Just about every kid in the dorm had BearShare or Limewire or some other filesharing program. If the music industry is losing less money, god bless them. I figured it was because of stuff like Pandora more than iTunes.
In terms of digital comics and whatnot, I actually have a really cool idea. We got an email from a digital comics company who wanted to do an interview with us. Guess what the interview is going to be about?
As a college kid in the itunes age, you came of age just as music piracy was at its peak with napster. Your generation is unique, probably. Napster, when it first came out, was wildly popular, and while the music industry thought it was because "holy shit this music is free," I don't think that was the factor. Because music was ALWAYS available for free. You could tape it off the radio. You could download it from IRC. The thing that made it different was the availability - every song ever available at a whim. It changed the world.
Itunes is very successful, and that wouldn't be possible if people didn't buy shit from it. On the other hand, shit like limewire faded away. Itunes offered the same availability as napster, but legitimate. I think most people would rather go with the safe, legal, guranteed quality, legitimate alternative over the illegal one. Unless the illegal one is vastly inferior.
Now I don't think legitimate digital comics are vastly inferior. They do some things right, like DC's day and date, and the trouble the providers go through to make the reading experience wotk on various devices.
But a year or two ago, it was woefully inferior, and I think that, more than anything, led to the massive rise in comics piracy.