Planet Money has a really interesting segment on Tom Burrell, who started out in the mailroom of a Chicago advertising firm in 1961 and ended up profoundly changing the way advertisers talk to non-white audiences.
At the time, if advertisers wanted to reach both white and black audiences, it was customary to conceive, write, and shoot material featuring white actors, and then reshoot the same ad with black actors. As Burrell rose in the ranks, he pushed to do better. His slogan was "black people are not dark-skinned white people," and his own worked served as example. He reimagined the Marlboro Man as a suave, black urbanite, and was behind the famous (and infamous) McDonald's "Calvin" campaign, which depicted a young black man's hiring and eventual promotion to manager at a McDonald's in his neighborhood.
Burrell called his method "positive realism," the idea that advertisers can reach audiences by creating authentic portrayals of their realities. He didn't end up eradicating "one size fits all" advertising, of course, but today, the writing's on the wall: changing demographics have birthed what marketers are calling "multicultural superconsumers," and Burrell's philosophies are probably more relevant than ever.