For ORCID, the organization that maintains the system of unique and persistent identifiers and associated metadata used by researchers and contributors to document their identities along with their publications, conference presentations, professional histories, education, and other professional metadata, conducted a set of interviews with academic book publishers, service providers, and funders to gain insight into the reasons for the slow adoption of ORCID for books, despite its widespread use for journals. The result was a report documenting the differences in workflows, motivations, technologies, and disciplines characteristic of academic book publishers, especially as contrasted with those of journals, and a providing a set of recommendations for increasing awareness and usage of ORCID in books.