Carrico, S. B., Cataldo, T. T., Botero, C., & Shelton, T. (2015). What cost and usage data reveals about E-book acquisitions: Ramifications for collection development. Library Resources & Technical Services, 59(3), 102-111. Retrieved from http://search.proquest.com/docview/1700405848?accountid=130717
In this study, a team of librarians from the University of Florida sought to determine the most efficient and cost effective way of acquiring e-books. They looked at three different methods: e-books acquired in large publisher packages; single-title e-books selected through firm orders; and e-books purchased through two patron-driven acquisitions plans. They also compared the results across three different disciplines: humanities and social sciences, science-technology-engineering-mathematics, and medicine.
They found that patron-driven acquisitions were the most effective method of acquiring e-books for the humanities and social science disciplines. E-books acquired via large publisher packages and single title selection showed a high percentage of non-use.
However, when it came to the other two disciplines, they found that acquiring e-books through large publisher packages was most efficient. The books showed high usage, and very low cost per usage. They determined that selecting individual books was not as effective because of the staff time involved.
Despite the study being specifically for a university library, I did find the article to include some helpful information. I’m not positive how the public library I work for acquires e-materials, but I do know that it does do patron driven acquisitions, and that when an electronic title is requested, the library acquires it very quickly, usually within 24 hours.