Who is Using Data and Why? developed a tool to track Dataverse Network user information consistent with the needs of data owners and collection administrators as well as compliant with American Library Association privacy policies. The Dataverse Network Project is an open-source application for publishing, citing, and discovering research data. This project resulted in Guestbook functionality to allow data owners to gather information on the people who download, analyze, visualize, or otherwise make use of their data. Data owners can choose from a set of basic identity fields (e.g., name, institution) and add custom questions; they can set them to be required or optional. The benefits of the Guestbook include the ability to demonstrate data sharing, the collection of data to buttress the case for continuing project funding, and the satisfaction of requirements for data owners to provide information about data usage, all increasingly important in the funding process.