Exactly how the marketing funnel jobs The earliest variation of a sales channel that I'm able to locate is this from 1904 by Frank Hutchinson Dukesmith, editor of the Salesmanship magazine Below, Dukesmith presented the principle of 4 stages that lead to a sale: Focus, Rate Of Interest, Need as well as Sentence. Nearly 50 years later, an advertising and also sales executive in the pharmaceutical sector, Arthur F Peterson, released the following picture in his book, Drug Marketing, Explaining, and also Sales Educating: