In his book, THE 21 INDISPENSABLE QUALITIES OF A LEADER, John C. Maxwell tells the story of Lester Wunderman.
"In 1947, Lester Wunderman was arbitrarily fired from his advertising job in New York. But the young man knew he could learn a lot from the head of the agency, Max Sackheim. The next morning, Wunderman went back to his office and worked just as he had before--but without pay.
Sackheim ignored him for a month, but finally walked up to Wunderman and said, "Okay, you win. I never saw a man who wanted a job more than he wanted money."
Wunderman went on to become one of the most successful advertising men of the century. He is known as the father of direct marketing.