What is the network effect (Theodore Vail)? Network Effects describes the phenomenon how the value of a good or service increases as more people start to use that good or service.

What is ‘loop theory’? (Norbert Wiener) Using data to predict what is going to happen next

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