 In his book “Rational Ritual” (2001), Michael Suk-Young Chwe points out the importance of the size of groups for which common knowledge gets established. A brand name that is common knowledge in a large group is worth a lot of money. Chwe analyzes the example of advertisements broadcasted during the American football Super Bowl. He compares the enormous cost of making something common knowledge by means of such advertisements to the obvious benefits. Part of the benefit is in the fact that the advertisements create common knowledge. An important consideration when deciding to buy a smartphone of a particular brand, for example, is the knowledge that others are going to buy the same model too.