My argument is that at *some* point, most digital content consumers will realize, either through frustration with a store/checkout process, digital pricing dissatisfaction, etc, that they could just as easily get the content they desire for free, almost as fast, almost as conveniently. The key here is almost, but the reciprocal is "free".
I think if you ask most 18-35 year olds who buy digital content, that they do so out of a sense of pride and honor, not ignorance to alternatives.
The key point here is that digital commerce DOES NOT work with DRM. Even apple, one of the curmugeonist of all curmugeons, realized this and stripped their music store of the ever-annoying and sales-killing DRM.
Consumers buy digital content as opposed to torrenting for the same reason that conventional shoppers carry a book up to the cash register and pay for it as opposed to walking out with. I was shopping at a book store the other day, and noticed that the RFID security tag was just laid inside between two pages in a book I really wanted. I made another purchase, and made a point to hide the RFID tag, which had fallen out, back as intended. Why did I do this? Why didn't I just walk out with the book?
The reasons could be varied, but they must be drawn from the pool of: conscience, honor, fear of punishment or social condemnation, guilt.
In our digital realm, conscience is not a big factor, as easy access to digital content is common now, and is even championed as a right by many. Fear of punishment is not an issue with most media, as viable alternatives to get music, books, and videos, that are more secure than bit torrent, and easily navigated by even the most basic computer user. Social condemnation is not a factor, as I see boyfriends/parents/spouses scoff at a partner/child for wanting to buy a dvd/book/cd, commenting that they "can just get all that for free".
So all that is left is the honor system, or the aforementioned convenience factor. Enter netflix. Netflix represents the ideal of how media companies, who in the past relied on retail sales can completely co-opt the internet piracy "problem" to actually increase their market share. I know of very few people who downloaded movies pre-netflix who still do. Convenience was the issue. Those that buy comics, books, and especially cds often cite the need to show financial and personal support with the creator.
In all these cases, easy alternatives to a digital purchase exists, but people, when given an alternative that is about as convenient, will choose to pay. This is the honor system defined, and this is why a DRM-free used CD key market will prosper even better than the current digital video game market.