Amazon’s business model has long been dependent on resellers of used books and other merchandise. But a U.S. patent that Amazon Technologies in Reno, Nev., received last week indicates that the mega-retailer has its sights on digital resale, including used e-books and audio downloads. According to the abstract, Amazon will be able to create a secondary market for used digital objects purchased from an original vendor by a user and stored in a user’s personalized data store.

Boston-based ReDigi opened the first marketplace for pre-owned digital music, which it launched in late 2011, redigi.com. Once a lawsuit that Capitol Records filed in U.S. District Court in Manhattan over the way it handles music downloads is behind it, ReDigi plans to expand into e-books and other digital items. In a press release issued yesterday, ReDigi commented that “the Amazon patent is further proof that the secondary market is the future of the digital space and that there is no turning back.”