Amazon Technologies has been awarded a U.S. patent for a “used digital content marketplace” that would include the ability for consumers to buy and sell ebooks and audio downloads.

According to the Washington Post, the patent was filed in 2009 and awarded on Jan. 29.

In 2012, a U.S. company called ReDigi, billing itself as the world’s first pre-owned digital marketplace, became embroiled in a copyright infringement lawsuit with Capital Records over its sale of used digital music. ReDigi has made clear its plans to expand into the ebook market once the lawsuit has been settled, responding to the Amazon news with its own statement: the Amazon patent is further proof that the secondary market is the future of the digital space and that there is no turning back.