Build story · South Africa · 1938–2018
De Beers: ‘A Diamond Is Forever’ creates a tradition
De Beers, which controlled most of the world's rough diamond supply, used advertising to make diamond engagement rings a near-universal tradition — then faced a threat from lab-grown diamonds.
By Shivam Bhandari · Reviewed 31 October 2026 · How we write
by the numbers
- ‘A Diamond Is Forever’ line
- 1947
- Japan campaign begins
- late 1960s
- Lightbox lab-grown brand
- 2018
What happened
In the 1930s diamond demand was weak and De Beers, which controlled most global rough diamond supply, hired US agency N.W. Ayer to change attitudes. Campaigns linked diamonds with romance and commitment. In 1947 copywriter Frances Gerety wrote the line ‘A Diamond Is Forever’, which also discouraged people from reselling diamonds.
The share of American brides receiving a diamond engagement ring rose dramatically in the following decades, and the ‘two months' salary’ guideline set expectations for price. De Beers ran a similar campaign in Japan from the late 1960s, where diamond engagement rings were previously rare, and they became common within about 15 years.
De Beers' supply control weakened from the 2000s, and lab-grown diamonds — chemically identical and much cheaper — became a serious threat. In 2018 De Beers launched its own lab-grown brand, Lightbox, at low prices.
Timeline
- 1938
De Beers hires N.W. Ayer.
- 1947
‘A Diamond Is Forever’ coined.
- 1967
Japan campaign launched.
- 2018
Lightbox launched.
what made it work
- Linked a product to life's most emotional moment.
- Controlled supply to protect prices.
- Discouraged resale to keep diamonds off the market.
the lesson
Marketing can turn a product into a tradition — but control built on scarcity is vulnerable when technology changes supply.
Apply it to your business
- 1Link your product to meaningful life events.
- 2Set clear social norms around buying.
- 3Watch for technology that could undercut scarcity.
Laws at work in this story
Figures are rounded and drawn from public reports, company filings and widely cited coverage at the time. Check the company's latest filings before relying on any number.