It seems like a tradition as old as marriage: a proposal, a ring, a diamond. It isn’t. As the BBC has pointed out, you can read through 19th-century literature and find almost no mention of diamond engagement rings. The tradition as we know it was built, to a remarkable degree, by one company’s advertising.
A company that controlled the supply
De Beers, founded in 1888, came to dominate the diamond business. From its early years until the start of the 21st century, it controlled roughly 80% to 85% of the distribution of rough diamonds and was widely considered a monopoly.
Controlling supply, though, is only half of a business. De Beers also needed steady demand, and diamonds had a problem: they are durable and, in principle, can be resold. A large secondhand market would compete with new stones and push prices down.
Four words
De Beers hired the Philadelphia agency N.W. Ayer & Son to promote diamond engagement rings in the United States. In 1947 an Ayer copywriter named Frances Gerety wrote the line: “A Diamond Is Forever.”
The campaign launched in 1948. Its message did two jobs at once:
- It tied diamonds to eternal love. A diamond became the natural symbol of a commitment meant to last a lifetime.
- It discouraged resale. If a diamond is forever, you don’t sell it. Stones stayed in families instead of flowing back into the market, which protected prices.
How the tradition took hold
Over the following decades, De Beers’ advertising built the idea that a proper engagement meant a diamond ring, and that the ring should be expensive. The BBC described the effect bluntly: De Beers managed to convince generations of men and women that the only acceptable symbol of an engagement was a diamond ring, and in doing so changed Western culture.
The slogan became so familiar that it likely inspired the title of Ian Fleming’s James Bond novel Diamonds Are Forever, and the film and theme song that followed.
Recognition, and scrutiny
In 2000, Advertising Age named “A Diamond Is Forever” the best advertising slogan of the 20th century. Gerety died in 1999.
The campaign has also drawn critical attention. A well-known 1982 article in The Atlantic, “Have You Ever Tried to Sell a Diamond?”, examined how the industry’s marketing supported high prices and why reselling a diamond often returns far less than its purchase price. More recently, the rise of lab-grown diamonds, which by 2025 were reported to cost roughly 90% less than mined stones, has challenged the idea of natural diamonds as uniquely precious.
Why it worked
- It attached a product to a ritual. Once the ring became part of the proposal, demand renewed itself with every new couple.
- It made the purchase emotional. Nobody haggles hard over a symbol of eternal love.
- It served the business model. The romance and the resale problem were solved by the same four words.
Few slogans have shaped behavior so deeply that people forget it was ever advertising at all.