Building on the theoretical proposals of Kevin Guthrie and others concerning the transition from print books to e-books in academic and health sciences libraries, this paper presents data collected using the MINES for Libraries® e-resource survey methodology. Approximately 6,000 e-book uses were analyzed from a sample of e-resource usage at thirteen academic and health sciences research libraries between July 2009 and June 2013. The authors report on findings about e-book usage and propose explanations regarding how the adoption path from print books to e-books differs from the growth in use of e-journals and the associated decline in print journals usage.