As long as the sale is legitmate (meaning the seller isn’t keeping a copy for himself) this would work out really well for the lesser money fortunate users. Say I buy a song for $.99, and I hate it, I should be able to sell the license for whatever, say $.49 (optimally using DRM to actually transfer ownership so that I won’t be able to play the song anymore). I could see this becoming really popular buy there are many ways to steal this music that might prevent this from happening. Such as I buy the song, burn it to CD, sell the license, then rip the CD into MP3s (or whatever format). Now I have the song, and some of my money back. I guess the only way this system would ever work is if it’s limited to media that has DRM settings that do not allow the burning to CD (although there are still ways around thath such as playing the song and recording via a digital loopback or analog loopback). It’s a never ending cycle so I guess ultimately I have to agree with eBay and what Apple will soon say… you cannot sell or distribute the songs you purchase from iTunes. Is this fair? No, but I can’t think of a secure way to allow such transactions without having easy ways to own music illegally after you purchase it and sell it off. This could really hurt online song sites as they are struggling as is (except iTunes) and people would rather buy their music for $.49 on eBay than $.99 on iTunes.