C. HOPKINS (1866-1932) is still renowned today for developing such marketing innovations as coded coupons that could be used to track the success of varying offers. His methods are still prized for their efficacy today. In this groundbreaking 1923 work, written after he retired as president and chairman of one of the world's biggest ad agencies, Hopkins shares the secrets of successful marketing that are just as relevant today as they were almost a century ago. Learn: . how advertising laws are established . the importance of just salesmanship . why businesses must offer service . mail order advertising: what it teaches . what makes headlines effective . understanding customer psychology . how to use art in advertising . how to use samples . the best way to test campaigns . the impact of negative advertising . and much more.