A Look at Metcalfe's Law

A look at long quoted Metcalfe's law, about how value grows as networks grow. It has been the 'rule' of Web 2.0, in GigaOm:

' ... Networks — be they telecom, social, transportation or otherwise — are the fabric of modern society. They provide immense value to consumers and businesses alike, enhancing mutual relationships and enabling the distribution of goods, services and information. But does this value grow as the size of the networks grow? And if so, how much? .... '