Dunbar’s number is a suggested cognitive limit to the number of people with whom one can maintain stable social relationships—relationships in which an individual knows who each person is and how each person relates to every other person.

A feedback loop is a concept found in systems theory. Feedback loops provide information to an organization about system successes and problems. Success results in a positive feedback loop and problems create a negative feedback loop.

Vail used the concept of Network Effects to build AT&T into a monopoly of telephone communication in the early 1900s. … There are also Indirect Network Effects, which occur when more customers indirectly increase the value of a product of service.