Whether or not you take a constructivist view of education, feedback on performance is inevitably seen as a crucial component of the process. However, experience shows that students (and academic staff) often struggle with feedback, which all too often fails to translate into feed-forward actions leading to educational gains. Problems get worse as student cohort sizes increase. By building on the well-established principle of separating marks from feedback and by using a social network approach to amplify peer discussion of assessed tasks, this paper describes an efficient system for interactive student feedback. Although the majority of students remain passive recipients in this system, they are still exposed to deeper reflection on assessed tasks than in traditional one-to-one feedback processes.