Claude C. Hopkins (1866-1932) was one of the great advertising pioneers. He believed advertising existed only to sell something and should be measured and justified by the results it produced. His book Scientific Advertising was published following his retirement from Lord & Thomas, where he finished his career as president and chairman. This book was followed by his autobiographical work My Life in Advertising. Hopkins has been credited with popularizing tooth brushing, as a result of his campaigns for Pepsodent. Hopkins was much more interested in direct marketing than branding advertising. He believed advertising was more about scientific results than image.