Understanding Social Networks: Theories, Concepts, and Findings

[With marketing] personal contact is most effective, if one can find a way to start a snowball rolling. Marketers call this 'viral marketing.' [In this image] researchers tracked recommendations for a Japanese graphic novel and illustrated the spread in a dense network. (Kadushin, 9)

Each of these five-person cliques is totally connected and mutual. But no one can be a member of the other clique without all ten being connected and mutual. (Kadushin, 47)