The interwar years in Britain are regularly referred to by historians and literary commentators as the Golden Age of detective fiction (c. 1920–1940). This article focuses on the Collins imprint the Crime Club, established in 1930. It assesses the significance of this imprint in the context of the Golden Age, with a focus on its commercial animus, drawing on theories about class-based markets and the commercialization of print culture. The article examines the marketing methods used by the Crime Club to promote its titles, such as newsletters and card games, and takes into consideration the arguments of 1930s literary critics. It aims to show that detective fiction had a significant role in the commercialization of print culture during the 1930s and that its success heavily relied upon the support of a middle-class readership.