This essay examines Romantic-era circulating libraries as a case study in the ways that institutions rather than individual authors create literary subgenres. The argument draws upon sociologically oriented research in literary and media studies and draws analogies between the history of the novel and the history of cinema. The growth of circulating libraries in the late eighteenth century created new markets for popular fiction, and this in turn spurred the creation of novelistic subgenres and formulas such as the gothic novel, the historical novel, and the season novel as means to respond to readerly demand for new titles. Circulating library catalogues and the novels themselves provide evidence of the ways that novelistic titles and subtitles signal generic affiliation to readers through keywords.