Abstract
Patron-driven acquisition for print books has been around for a while. For example, the university of Vermont Library worked with ybP to set up PDA for print books in 2007, based on rush ordering in response to patron requests from the library catalog. But the old model of invoicing upon acquisition still held. The real growth in the patron-driven business model has been enabled by combining two innovations: eBooks and usage-triggered invoicing (a more accurate term than patron-driven acquisition but with a much more awkward acronym). Librarians can now select eBooks for the collection via approval and/or manual selection, obtain access for patrons, and greatly expand the size of the library while only paying for those titles that are triggered by a specific level of usage.