redigilogoTechCrunch reports that digital music resale firm ReDigi, who I mentioned back in February, is actually launching its eMarketplace to allow people to buy and sell “pre-owned” digital music. ReDigi claims that it has consulted with lawyers and determined what it’s doing is legal, but I’m not so sure.

ReDigi hopes to succeed where others have failed by designing a marketplace that is not about file sharing, but is instead a method of “facilitating the legal transfer of music between two parties”. Really, the key here is that the startup’s technology is able to actually verify that a track was properly purchased (or acquired) by the person looking to resell, and manages items posted for sale within the sellers’ music libraries to prevent multiple copies from being auctioned. (Which should, in practice, protect the seller from copyright infringement.)

ReDigi deletes songs from your hard drive and associated music players after you sell them, holding them on its own servers until it passes them to whoever buys them. The firm claims it will be selling pre-owned digital songs “at a fraction of the price currently available on iTunes.”

As I’ve said before, I find it highly doubtful that the record labels will let ReDigi get away with this for very long. Content vendors tend to hate the used resale market with a fiery passion, and I can’t see them letting ReDigi come in and throw away the biggest advantage (from their perspective) of digital—that once sold, a digital item can never be resold without violating copyright.

Of course, if ReDigi is able to get away with this, expect similar resale services for used e-books to be right around the corner.