This article uses data from a study of college students’ digital reading and writing to examine the influence of interface on literacy activity within participatory online spaces. While most existing work treats activity within these spaces largely as a function of individual interest in a space’s content, students’ firsthand accounts suggest that interface features and design play a significant role as well, particularly as students transition from one form of engagement or activity to another. Using Teena Carnegie’s framing of the interface as digital exordium, the author argues that, since participatory interfaces and the composition classroom share several central goals, students’ experiences with interface offer important lessons for translating that engagement to an academic setting.