Linkng diamonds to romance through public relations,, movies like Diamonds are Dangerous, Adventures in Diamonds, news stories fed to the press, radio... 1919-onwards
"...N. W. Ayer suggested that through a well-orchestrated advertising and public relations campaign, it could significantly alter the "social attitudes" of the public at large and thereby channel American spending toward larger and more expensive diamonds instead of "competitive luxuries." Specifically, the Ayer study stressed the need to vitalize the association in the public's mind between diamonds and romance. Since "young men buy over 90% of all engagement rings," it would be crucial to inculcate in them the idea that diamonds were a gift of love: the larger and finer the diamond, the greater the expression of love. Similarly, young women had to be encouraged to view diamonds as an integral part of any romantic courtship. The study found that there was already an increasing number of marriages among middle-income wage-earners who were "the backbone of the diamond market," and that, if properly cultivated, this trend could provide fertile grounds for diamond sales in the future..."