The issue in my mind is that online social networks aren’t currently granular enough in their definition of relationship – and that’s a key requirement for platforms that connect people in physical space.

I can be friends with someone in one situation and not what to meet them in another. At the same time I don’t want to have to specify a relationship parameter for everyone – both because it’s to time consuming and because it doesn’t suit the flexible way that people manage the different types of relationships they have with people in different situations.

In other words it’s got to learn – possibly notifying me of potential social connection and then using proximity (blue tooth etc) between devices to deduce whether connection was sought or avoided, GPS to deduce situation (work, shopping etc) and then layer on some of the relevance stuff you’re working on to get at the psychological intangibles and you could build programmatically something similar to the situational rules that people use to govern their interactions in physical space.