De Beers

Diamonds are not rare. The Earth's crust contains enough diamonds to give every person on the planet a cupful. The reason a diamond engagement ring costs two months salary is not geology. It is advertising psychology executed at civilisation scale. Cecil Rhodes founded De Beers in 1888 and understood that the way to create value from an abundant stone was to curate its availability and build a narrative around its meaning. He bought up every diamond mine he could find, and the empire began. The advertising campaign that launched in 1947 did not just sell diamonds. It rewrote cultural behaviour. De Beers hired the advertising agency N.W. Ayer, which placed diamonds in movies, on the fingers of celebrities, and wove them into aspirational storytelling across every medium. They established the idea that a man should spend two months salary on an engagement ring, a guideline that had never existed in any culture before De Beers popularised it. They created the slogan a diamond is forever, which served a dual purpose. It made diamonds sound romantic and it told consumers that a diamond should never be resold, eliminating the secondary market that would have revealed how common the stones actually were.