We explore the potential of learning from reading discussions in social network settings. Undergraduates were asked to read an argumentive discussion between students of a closed, course-related Facebook group. The discussion revolved around a social-economic-ethical, ‘hot’ topic of debate and contained several links to online resources in support of the discussants’ opinions. Based on previous research on argumentive discourse style, two different online discussions were created to reflect either a disputative or deliberative discourse goal, while controlling for all other verbal content. Students in a control condition only received the links to the same online resources, without the discussions. Following the reading phase, declarative knowledge on the topic was significantly lower in the disputative discourse condition, but no differences were found between the deliberative argumentation and the control condition. Reading behavior measures (time-on-task, time spent reading the online information resources, number of online information sources, time spent reading the discussion) could not account for the differences in knowledge performance. A program for future research is outlined to explore the effects of learning through reading discussions, the role of argumentive style, and the affective and cognitive processes underlying them.