One of the most recognizable slogans in the world of advertising dates back to an ordinary evening of 1947. In those years, women in marketing were a rarity, as they were mostly hired to promote products targeted at females. Mary Frances Gerety was no exception – a copywriter at the N.Y. Ayer & Son agency, working on the account of the diamond mining giant DeBeers. That same night, having just finished working, she remembered she had a meeting with the De Beers executives scheduled for the following morning. Overwhelmed with exhaustion, she scribbled the phrase “A diamond is forever” on a piece of paper before going to bed. Little did she know that this unassuming four-word tagline would become the most recognized slogan of the 20th century.
While Mary Frances Gerety’s legacy has only recently started to gain recognition, De Beers has long been celebrated as the company that paved the way for the modern diamond industry. Its history dates back to 1888 when the prominent British businessman Cecil Rhodes founded De Beers Consolidated Mines. Soon after, the company established an almost full monopoly on diamond mining worldwide. In 1929, German-born entrepreneur Ernest Oppenheimer took over the chairmanship. Knowing that monopolistic reign could only be maintained as long as diamonds remained scarce, he wanted to leverage the firm’s unrivaled market power, whilst hedging against the risk that new mine discoveries would oversaturate the market.
This is why in 1938 De Beers hired the advertising agency N.Y. Ayer & Son to help them revive interest in diamonds after demand had plummeted during the Great Depression. In 1948, the account was entrusted to Mary Frances Gerety, who decided to transform the conventional perception of diamonds by permanently associating them with love. Following the devastation of the Second World War, people were unwilling to spend money on the precious gem, which was considered a luxury reserved only for the most affluent. Gerety set out to challenge this understanding and establish a new status quo for what diamonds symbolized. The slogan “A diamond is forever” perfectly encapsulated the profound emotion that is embedded within this milestone purchase. The tagline cemented the idea that the only material thing that could symbolize pure and everlasting love was the equally uncorrupted and indestructible stone.
The campaign proved to be an unprecedented success for both companies involved. By 1979, De Beers’ diamond sales within the States had skyrocketed from $23 million to $2.1 billion, which corresponded to a change in their marketing budget from $200,000 to $10 million yearly. People outside the wealthy elite now saw the diamond engagement ring as a necessary prerequisite for marriage – while in 1940 only 10% of future brides were being proposed to with the precious stone, 50 years later this number had risen to 80%. Simultaneously, the campaign established the unspoken rule that such a personal and emotionally charged possession should never be sold on the secondary market, which ensured prices and exclusivity would remain high.
But perhaps the most brilliant move on the part of De Beers was how they steered the campaign in a way that created expectations around engagement. They started issuing advertisements with the tagline “How can you make two months’ salary last forever?”. These ads featured a fine print which encouraged customers to follow the 4 C’s rule when buying diamonds – cut, color, clarity and carat. These initiatives quantified the “cost of love” and made consumers feel educated about their purchases, which further consolidated the diamond as the go-to engagement stone. DeBeers had finally bridged the gap between the ordinary buyer and the industry that once seemed so distant – diamonds truly had become a “girl’s best friend”.
“A diamond is forever” was voted the most identified slogan of the 20th century by the revered media company Ad Age – and rightfully so. It is an unparalleled case in marketing history where promotion went beyond the individual firm and fully transformed the industry. By establishing an identity between love and diamonds, De Beers navigated advertising in a way which transcended luxury and set the status quo of what jewelry stands for today.