“The Ayer Idea In Advertising,” N. W. Ayers & Son, Philadelphia, 1912.

Credit: Hartman Center for Sales, Advertising & Marketing History, Duke University Rare Book, Manuscript, and Special Collections Library http://library.duke.edu/digitalcollections/eaa/

No form of literature has had a greater impact on Americans in the past 150 years than advertising. Here, too, Pennsylvanians were pioneers. N. W. Ayer & Son, the nation’s first advertising agency, was founded in Philadelphia in 1869. Before Ayer moved to New York City in 1973, its famous slogans included "When it rains it pours” (Morton Salt, 1912), "I'd walk a mile for a Camel", (R.J. Reynolds Tobacco, 1921), and "A diamond is forever" (De Beers, 1947). In 1912, the company published this pamphlet to promote its industry and its own services. “Advertising” it notes, “is a way by which people are told why they should have your goods and, at the same time, taught how they may identify them.”