Amy Fry has published "Ebook Rate of Use in OhioLINK: A Ten-Year Study of Local and Consortial Use of Publisher Packages in Ohio" in College & Research Libraries.
Here's an excerpt:
This paper examines publisher ebook package use in the OhioLINK academic library consortium between 2007 and 2017 alongside use of the same titles at individual institutions. With nearly 100,000 titles acquired over 10+ years from three publishers and available to users at more than 90 institutions, the picture of ebook use this study presents is unique in its breadth and scope. The data show that, consortiumwide, close to 100 percent of titles were used, with their initial use overwhelmingly taking place within one year of their publication date. At individual institutions, the rate of use was far lower and never exceeded the rate of use of print books at the author’s own institution. These findings have important implications for how institutions approach ebook acquisition to maximize rate of use of ebook collections.