This essay discusses the philosophy, methodology, myriad conceptual dilemmas, and ultimate findings of the AHRC-funded French Book Trade in Enlightenment Europe (FBTEE) project. The project, which has been widely acclaimed, has created an "interpretational-relational database" to map the pan-European book trade of the celebrated Société typographique de Neuchâtel (STN), a large-scale Swiss wholesaler-publisher that operated between 1769 and 1794. The article showcases how careful database design and the provision of custom-designed digital tools and sophisticated but intuitive online interface allow users to compensate for complexities, uncertainties, biases, and gaps in the STN archive, particularly by customized data filters that allow them to search multiple subsets of data. The article argues that by intelligent application of these tools, we can create customized datasets that can stand proxy for the wider European book trade of the late eighteenth-century, and hence serve as a means to take the pulse of the later Enlightenment. Finally, it maps the future development of the project, and how further types of book-trade-related sources might be treated in the same manner as the STN archive in a single network of inter-operable projects to create a more rounded and comprehensive sense of the reception, communication, and transformation of ideas across space and time. More than the culmination of a book history project, this is surely one of the holy grails of cultural history, and hitherto a most elusive one.