The company says it has done "extensive research and have spent many hours with well respected law firms in Boston, NYC and LA" and believes the "marketplace will provide and protect the rights of consumers as they were provided for under US copyright act and the first sale doctrine."
ReDigi says it believes that just because a file has been digitized does not mean users should lose the right to re-sell their goods as if it were a physical object.
The new marketplace will as a forum for re-selling the digital tracks, first by verifying that the track was properly acquired and then "managing items selected for sale within the sellers music libraries to prevent multiple copies (protecting the seller from copyright infringement)." Finally, the company "facilitates an even greater level of copyright protection than the previous CD market."
ReDigi also donates a portion of all their revenue to the artist and their label, possibly opening a new revenue stream for the labels.
You can request an invite here: http://www.redigi.com/