The patent describes a way to sell apps and songs second-hand, but faces tough legal battle. (SHANNON STAPLETON/REUTERS)

Consumers may someday be able to buy and sell old e-books, apps and songs the same way campus bookstores sell used textbooks — at least if an Amazon patent ever comes to life.

The patent, which Amazon filed in 2009 and won on Jan. 29, imagines a digital resale marketplace where users can trade “digital objects” like e-books, songs, videos and apps. According to the patent, these items would live in the user’s “personalized data store,” presumably in the cloud. Selling a song would copy it to another user’s data store and delete it from the original owner’s.

The patent doesn’t mean such a marketplace is coming anytime soon — or at all — but it does show Amazon’s interest in wading into the contentious muck of digital resale rights.

According to a recent PaidContent report, consumers and publishers have contested the right to buy and sell “used” digital items for more than a decade, when the Patent Office addressed the issue in a congressional report (PDF). On one hand, many consumers and middlemen argue that if “you bought it, you own it” — and you should be able to share it, like a tangible book or song. On the other hand, music labels and publishers fear resale rights will erode their sales and profits.

At least two high-profile digital rights cases are before the courts right now, with verdicts expected later this year. Library associations have been active in Kirtsaeng vs. Wiley, a Supreme Court case weighing the rights of the buyers of copyrighted works. (Foreign books, in this case, though libraries also face tough restrictions around e-book lending.)

In another case, the digital music start-up ReDigi was sued by EMI, which claims ReDigi’s “online marketplace for used digital music” violated copyrights. ReDigi claims it takes extensive steps to protect against copyright abuse.

In a statement today, ReDigi said “the Amazon patent is further proof that the secondary market is the future of the digital space,” but implied that its marketplace was more copyright-friendly than Amazon’s.

That could matter in the future. Some industry-watchers, such as PaidContent’s Laura Hazard Owen, have suggested that Amazon’s patent prove problematic for ReDigi. And the outcome of the ReDigi case, will likely impact Amazon’s resale marketplace plans.

“ReDigi takes no position on the legality of this technique under copyright law,” the statement says, referring to Amazon’s copy-and-delete transfer patent, “but simply notes that it has been central to the music and publishing industries’ skepticism and opposition to a ‘used’ digital marketplace, and that the ReDigi Marketplace does not use this technique.”

Ironically, Amazon had a hand in starting the brouhaha over digital resale rights. According to Bill Rosenblatt, a consultant who has written widely on digital rights management, the issue flared up recently because retailers have made shareable music the norm. Amazon was an early proponent of rights-free music — it announced the launch of a DRM-free store in May 2007.

“Music buyers can return to treating their purchases as their property — reselling as they see fit or passing them on to their heirs,” one Post reporter wrote hopefully at the time.

But six years later, Amazon appears only inches closer to that goal.

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