By 1941, The advertising agency reported to its client that it had already achieved impressive results in its campaign. The sale of diamonds had increased by 55 percent in the United States since 1938, reversing the previous downward trend in retail sales. N. W. Ayer noted also that its campaign had required "the conception of a new form of advertising which has been widely imitated ever since. There was no direct sale to be made. There was no brand name to be impressed on the public mind. There was simply an idea -- the eternal emotional value surrounding the diamond." It further claimed that "a new type of art was devised ... and a new color, diamond blue, was created and used in these campaigns.... "
In its 1947 strategy plan, the advertising agency strongly emphasized a psychological approach. "We are dealing with a problem in mass psychology. We seek to ... strengthen the tradition of the diamond engagement ring -- to make it a psychological necessity capable of competing successfully at the retail level with utility goods and services...." It defined as its target audience "some 70 million people 15 years and over whose opinion we hope to influence in support of our objectives." N. W. Ayer outlined a subtle program that included arranging for lecturers to visit high schools across the country. "All of these lectures revolve around the diamond engagement ring, and are reaching thousands of girls in their assemblies, classes and informal meetings in our leading educational institutions," the agency explained in a memorandum to De Beers. The agency had organized, in 1946, a weekly service called "Hollywood Personalities," which provided 125 leading newspapers with descriptions of the diamonds worn by movie stars. And it continued its efforts to encourage news coverage of celebrities displaying diamond rings as symbols of romantic involvement. In 1947, the agency commissioned a series of portraits of "engaged socialites." The idea was to create prestigious "role models" for the poorer middle-class wage-earners. The advertising agency explained, in its 1948 strategy paper, "We spread the word of diamonds worn by stars of screen and stage, by wives and daughters of political leaders, by any woman who can make the grocer's wife and the mechanic's sweetheart say 'I wish I had what she has.'"
De Beers needed a slogan for diamonds that expressed both the theme of romance and legitimacy. An N. W. Ayer copywriter came up with the caption "A Diamond Is Forever," which was scrawled on the bottom of a picture of two young lovers on a honeymoon. Even though diamonds can in fact be shattered, chipped, discolored, or incinerated to ash, the concept of eternity perfectly captured the magical qualities that the advertising agency wanted to attribute to diamonds. Within a year, "A Diamond Is Forever" became the official motto of De Beers.
In 1951, N. W. Ayer found some resistance to its million-dollar publicity blitz. It noted in its annual strategy review:
The millions of brides and brides-to-be are subjected to at least two important pressures that work against the diamond engagement ring. Among the more prosperous, there is the sophisticated urge to be different as a means of being smart.... the lower-income groups would like to show more for the money than they can find in the diamond they can afford...
To remedy these problems, the advertising agency argued, "It is essential that these pressures be met by the constant publicity to show that only the diamond is everywhere accepted and recognized as the symbol of betrothal."
N. W. Ayer was always searching for new ways to influence American public opinion. Not only did it organize a service to "release to the women's pages the engagement ring" but it set about exploiting the relatively new medium of television by arranging for actresses and other celebrities to wear diamonds when they appeared before the camera. It also established a "Diamond Information Center" that placed a stamp of quasi-authority on the flood of "historical" data and "news" it released. "We work hard to keep ourselves known throughout the publishing world as the source of information on diamonds," N. W. Ayer commented in a memorandum to De Beers, and added: "Because we have done it successfully, we have opportunities to help with articles originated by others."
N. W. Ayer proposed to apply to the diamond market Thorstein Veblen's idea, stated in The Theory of the Leisure Class, that Americans were motivated in their purchases not by utility but by "conspicuous consumption." "The substantial diamond gift can be made a more widely sought symbol of personal and family success -- an expression of socio-economic achievement," N. W. Ayer said in a report. To exploit this desire for conspicuous display, the agency specifically recommended, "Promote the diamond as one material object which can reflect, in a very personal way, a man's ... success in life." Since this campaign would be addressed to upwardly mobile men, the advertisements ideally "should have the aroma of tweed, old leather and polished wood which is characteristic of a good club."
Toward the end of the 1950s, N. W. Ayer reported to De Beers that twenty years of advertisements and publicity had had a pronounced effect on the American psyche. "Since 1939 an entirely new generation of young people has grown to marriageable age," it said. "To this new generation a diamond ring is considered a necessity to engagements by virtually everyone." The message had been so successfully impressed on the minds of this generation that those who could not afford to buy a diamond at the time of their marriage would "defer the purchase" rather than forgo it.