A diamond slogan sold the idea of never selling the diamond.

How De Beers Made a Diamond Feel Essential

In the late 1930s, De Beers faced a problem of demand: diamond engagement rings were not yet a universal expectation, especially in the United States. The company hired the advertising agency N.W. Ayer to make diamonds feel like the natural symbol of courtship and commitment. Rather than simply advertise a particular ring, the campaign linked buying a diamond to love, status, and a lasting promise.

That strategy worked through repetition and social pressure as much as through product claims. Advertising appeared in popular media, while fashion coverage and celebrity associations helped make diamond rings seem like something couples were expected to want. A later De Beers slogan, “A Diamond Is Forever,” reinforced the idea that a diamond’s permanence made it an appropriate emblem of enduring love.

Scarcity Was Also a Supply Strategy

Diamonds are not uniformly rare in the ground. What matters commercially is the supply of stones suitable for jewelry—and who can bring them to market. For much of the twentieth century, De Beers exercised substantial influence over that supply through its mining interests and its Central Selling Organisation, which bought and distributed diamonds from producers. By managing how many stones entered the market, the company could help limit availability and support prices.

This did not mean De Beers controlled every diamond everywhere, or that advertising alone set prices. But control over a large share of supply gave the company unusual power to shape the market, while its campaigns shaped what buyers believed a ring should signify.

A Custom With a Price Tag

The familiar idea that an engagement ring should cost two months’ salary was a marketing rule of thumb, not an economic law. Its force came from making a personal purchase seem measurable—and from tying the amount spent to the seriousness of a relationship. The lasting achievement was not persuading people that every diamond was geologically scarce; it was helping turn a purchasable stone into a social expectation.