Digital platforms have established new arenas for scholarly communication. The two Academic Social Networking Sites (ASNSs) ResearchGate and Academia.edu provide infrastructures that fit into the basic structure of the predigital scholarly communication system. Drawing on infrastructures and organizations as significant features of the scholarly communication system and digital platforms, this article seeks to outline how platform-based scholarly communication relates to the predigital scholarly communication system. The ASNS were analyzed qualitatively by conducting an interface-walkthrough. The results show how the ASNS (1) represent novel infrastructures and organizations for scholarly communication, (2) generate new, complementary subfunctions for scholarly communication that challenge boundaries of formal and informal scholarly communication, and (3) distinguish from established scholarly communication infrastructures and organizations by relying on platform mechanisms such as network effects, commercialization and control of data.
