Just how the advertising channel works The earliest variation of a sales channel that I'm able to find is this one from 1904 by Frank Hutchinson Dukesmith, editor of the Salesmanship magazine Below, Dukesmith presented the idea of four stages that bring about a sale: Interest, Interest, Need as well as Sentence. Almost half a century later on, a marketing and also sales executive in the pharmaceutical sector, Arthur F Peterson, published the following picture in his publication, Drug Selling, Outlining, and Sales Educating: