But there are spaces between these two poles. There are a variety of real-world, directed processes that employ the techniques and tools of social media, such as online political organizing where people create, swarm around, and act upon ideas; and organizational uses of social software, where the tools are used in the service of various shared goals extrinsic to the tools.

These activities have goals and rules that are in part extrinsic to the system. But when social software works well in these contexts, it works in part because in draws upon the self- and other-motivated interests that make social media go in less directed contexts.

Good observation. I really just took interest from the literature — it’s been used for several hundred years, from “speculative interest” to “self-interest” and it captures the one important thing here: social media users must have an interest in social interaction (of some kind). This is not banking software. It’s completely voluntary and so must engage the interests of users (which will vary)….

On a finer point, interest is better than response. We sometimes fall to simple behavioralist descriptions built around a correlation between stimulus and response. Clearly that’s not going to work for social media, where the social dimension is richly nuanced and the communications provide a lot of ambiguity and many different ways of engaging and responding. So interest can still relate to intent, motive, and self-reflection; it can combine with subconscious interest or, at the other end, strategic interest. By saying interest we emphasize the user, not the design, and ascribe causality in action to where it belongs: in people.