I highly recommend this PBS Frontline documentary (available on line) on and about the persuaders.
From the site:
Each year, legions of ad people, copywriters, market researchers, pollsters, consultants, and even linguists—most of whom work for one of six giant companies—spend billions of dollars and millions of man-hours trying to determine how to persuade consumers what to buy, whom to trust, and what to think. Increasingly, these techniques are migrating to the high-stakes arena of politics, shaping policy and influencing how Americans choose their leaders.
In « The Persuaders, » FRONTLINE explores how the cultures of marketing and advertising have come to influence not only what Americans buy, but also how they view themselves and the world around them. The 90-minute documentary draws on a range of experts and observers of the advertising/marketing world, to examine how, in the words of one on-camera commentator, « the principal of democracy yields to the practice of demography, » as highly customized messages are delivered to a smaller segment of the market.
Depending on your point of view, truly fascinating and/or frightening. I was particularly interested by Clotaire Rapaille and how he turns market research upside-down. An extended interview of him is available along with others on a separate interviews page.