What is the network effect? (theodore vail)

The network effect is a case of an increased number of people participating in something which leads to an increased value. Vail said  “each little system would have been independent and self-contained without benefit to any other.” A telephone without a connection at the other end, Vail explained, “is one of the most useless things in the world. Its value depends on the connection with the other telephone — and increases with the number of connections.” 

What is the feedback loop theory? (norbert wiener)

The theory that our brains get used to doing something and it becomes second nature to do it. Eg walking – you don’t have to constantly think about the next step.

What is the dunbar number? (robin dunbar)

Dunbar’s number is a suggested cognitive limit to the number of people that one can maintain stable social relationships with (relationships where an individual knows who each person is and how each person relates to every other person)