Library collections contain significant analytics about the demand for and usage of course content that we are mining to guide advocacy and outreach for open educational resources. The NCSU Libraries has analyzed portfolios of request and usage data for this purpose. Data points such as general collection circulation, reserve use, and interlibrary loan requests all provide indicators of faculty textbook assignments and purchase alternative demand among students. Library request and usage data provide indicator signals of course content students are seeking to access through alternatives to standard purchase options. Librarians at NCSU compile usage data for required textbooks, compare it to course enrollment data, and identify courses and instructors for targeted alternative textbook outreach. Factors such as the demographics of enrolled students, course level, availability of content through the Libraries, and affordability of required content can influence the level of demand through the library. This presentation will outline the analytical techniques used to guide advocacy efforts and discuss the efficacy of that outreach in promoting alternatives to traditional textbooks.