The original post begs the question of "DOES DRM actually deliver revenue to the content owners." It assumes that it does and that therefore there needs to be some mechanism to enable DRM to do so.
As has been pointed out numerous times here on /. as well as techdirt and popehat and reddit and other places, that is NOT the case. The revenue that is gained goes to ENFORCEMENT, goes to HARASSMENT of "illegal downloaders"[sic - downloading is not illegal], but NEVER to the artists who created the content.
A better refinement of the question should read:
"What mechanisms could be used to ensure that the creators of content are compensated and their rights are not taken nor abused?" There are quite a few examples (in the sources previously cited) where artists put their content for downloads, and VOLUNTARY DONATIONS bypass the hoarde of middlemen thieves to make the artist wealthy. There are no "technical" mechanisms that can let someone read a book, listen to a song, or view a video that they cannot then make a copy. If you don't allow them to backup that copy, watch/listen/view it on multiple devices including car-audio or smartphone, they will make their own copy and no revenue will be afforded the creator.
A second mechanism is one where the content is EASILY made available for these uses, but incrementally the value-add is to the buyer who chooses to buy that other copy. For example: if I buy a Blu-Ray of BestMovieEver and for another $2 I can download it to my smartphone with chapters, subtitles, and all the features I'd want to see in an original creation (but won't get in a BR-rip) that's worth it.
If I buy a book from AMZ and for another $0 I can get it for my Kindle [reader on my smartphone] for ALL titles and it will NOT be pulled away later [like 1984] then that's a great value. Maybe for another $5 I can get a second copy stamped "Office Library" in big red letters on the softbound cover, so I can keep that in the office to read.
If I get an MP3 or two or three or an album, and for $5 I get a jewel box with a CD for the car, or a poster of the band... those are also value adds.
Key 1: technology will not prevent copying
Key 2: giving the content creator the revenue means removing all the thieves from the middle of the process
Key 3: getting "revenue" to exist means giving the buyer a "value-add" to purchase more, and thereby an incentive to purchase, rather than today's attempts to dis-incent the copying.
Good luck.
E