In relation to property, an exclusive right will, for the most part, arise when something tangible is acquired; as a result, others are prevented from exercising control of that thing.
The exclusivity agreement will prevent the proposed seller from negotiating a sale with any other potential purchaser for a fixed period of time.
[1] Most jurisdictions recognize a bundle of exclusive rights in relation to works of authorship, inventions, and identifications of origin.
In common law jurisdictions, exclusive rights have often been the codification of pre-existing social norms with regard to land or chattels.
However, such arguments can only be consistently justified through instrumentalism or consequentialism, as exemplified by the reasoning inferred in Article One of the United States Constitution that copyrights and patents exist solely "To promote the Progress of Science and useful Arts".