In the real world, lending a book to a friend or selling your used music collection isn’t exactly groundbreaking. In the digital world, it’s patentable.

Amazon.com has been awarded what appears to be a broad patent on a “secondary market for digital objects” — a system for users to sell, trade and loan digital objects including audio files, eBooks, movies, apps, and pretty much anything else.

The patent, originally filed in 2009 and granted on Jan. 29, covers transferring digital goods among users, setting limits on transfers and usage, charging an associated fee, and other elements of a marketplace for “used” digital goods.

The Seattle company is already implementing the approach in its feature for lending Kindle books, but the bigger question is whether the newly granted patent could impact others pursuing similar businesses, such as ReDigi — a “pre-owned digital marketplace” that has attracted legal attention from major music labels.

[Follow-up: Rival shrugs off Amazon patent on resale of ‘used’ digital goods]

One of features of Amazon’s approach is the ability to “maintain scarcity” of digital objects. From the patent …

… an object move threshold (“OMT”) may be set. The OMT may limit the number of transfers of a used digital object to other personalized data stores when the used digital object has been moved more than a threshold number of times, thereby helping to maintain the scarcity of the digital object in the marketplace. For example, a popular used digital object such as a song may have an OMT of three, only allowing three permissible moves of the song to other personalized data stores. After the OMT is reached, the used digital object is no longer permissibly moveable to another personalized data store…

Read the full text of the new Amazon patent here.