Network Effects describes the phenomenon how the value of a good or service increases as more people start to use that good or service. … This phenomenon was first described by Theodore Vail in 1908.

Cybernetics is applicable when a system being analyzed incorporates a closed signaling loop—originally referred to as a “circular causal” relationship—that is, where action by the system generates some change in its environment and that change is reflected in the system in some manner feedback that triggers a system change. Use predicted data to determine future actions. ‘When we walk why don’t we fall over.’

The theory of Dunbar’s Number posits that 150 is the number of individuals with whom any one person can maintain stable relationships.