Naturally, people are influenced by their neighbors in the social network — the more friends you observe doing something the more inclined you are to do it – and, naturally, there are diminishing returns – if 99 friends are doing it, then seeing the 100th one do it doesn’t change your behavior much.
However, there’s an important psychological effect – the 0-1-2 effect — that runs contrary to diminishing returns. According to Jon Kleinberg
the probability of joining an activity when two friends have done so is significantly more than twice the probability of joining when only one has done so
According to Peter Denning
An innovation is a transformation of practice in a community. It is not the same as the invention of a new idea or object. The real work of innovation is in the transformation of practice.
The 0-1-2 effect suggests that a successful innovator must not merely make initial converts, but also encourage them to be visible about it.