This is what I immediately saw on Jackie Huba's posting Cycle of a Fan.
Participation is the power source to any energy created by fans. Participation is crucial to the cycle of fandom.
I'm not sure how I would draw it, but participation could be a circle that encompasses everything inside Geno's diagram, with key activities identified that engage fans at every point.
I agree. The line of the circle could begin thin representing a one-to-one relationship, and end wide with many strands representing the many people participating with the person.