“Demand-driven acquisitions (DDA) programs have become a well-established approach toward integrating user involvement in the process of building academic library collections. However, these programs are in a constant state of evolution. A recent iteration in this evolution of ebook availability is the advent of large ebook collections whose contents libraries can lease, but not own only if they choose to do so. This study includes an investigation of patron usage and librarian ebook selection by comparing call number data generated by usage of three entities: (1) an ebrary PDA; (2) Academic Complete, which is a leased collection of ebooks; and (3) subject librarian selections based on the YPB approval plan at Iowa State University. The context is provided through a description of the development and evolution of demand driven acquisitions programs with an analysis of where libraries have been and where they are going with enhancing the collection development in academic libraries.”