(If one wants to do that road, one should probably start reasoning from the "killer app" of a novel network model. The killer app of the web was HTML, and specifically the hyperlink combined with the URL, which allowed for association of information in a way that hadn't been possible before. It'll be hard to one-up that, but if someone could find a way to do it that would be hard for HTML to just grow to consume, there may be room for a novel information service).