ABSTRACT
Demand-driven acquisition (DDA), also commonly referred to as patron-driven acquisition (PDA), is a process used by libraries to provide a large pool of content to their users while only paying for portions of that content at the point of use. Typically, records for that content are displayed in the library’s catalog or discovery system, and when patrons find those records and access that content, a purchase or temporary lease of that particular title is triggered. DDA has most commonly been used for e-books, but it has been used for other formats as well.
