If you use Excedrin for your headaches, you are among 18 percent of the population and you are what Chris Kuenne terms “an aggressive medication believer” who wants to nuke your headaches. Excedrin does that because has two relievers in it, plus caffeine, and the caffeine makes the other drugs work faster.

At the Princeton meeting of the Association for Corporate Growth (ACG) on February 4 at the Westin, Kuenne told how his firm, Rosetta, gains market share with its trademark strategy, “personality-based segmentation,” which offers mathematical ways to connect behavioural and attitudinal data.

Rosetta told its Excedrin client (at the time, Bristol-Myers Squibb) to focus everything – ads, packaging, PR, whatever – on that niche market of aggressive medication believers, those who want meds, want to use them aggressively, and believe that they will work. “We told them to spend no dollars on the other 82 percent of the market.”

Personality-based segmentation has worked, for Rosetta, in five vertical markets: healthcare, finance, consumer/retail, B2B web-based technology, and travel. With $130 million in revenue in 2008, Rosetta is now among the top 10 digital ad agencies in the United States and the largest privately held one.

His advice to would-be entrepreneurs: if one or two things fascinate you, that could be your cues for business ideas. Some of his other success strategies:

Focus on one great idea.

Focus on the right industries and serve the right marquee clients.

Obsess over quality and client impact.

Hire the smartest people.

Run like a publicly held company from the beginning. Have a major law firm, major accounting firm “and grow into them.”

Those strategies helped, but so did timing. The dotcom bubble had come and gone when Rosetta was starting up. So it had time to reinvent itself and ride the next wave.

Kuenne made his first sale at J&J;, where he got his start. After graduating from Princeton University in 1985 and getting a Harvard MBA, he worked at J&J; for 10 years, then did a stint at Nelson Communications. He spun out his part of Nelson Communications into Rosetta in 1998, setting up at the Carnegie Center. In 2005 he “moved downstream” and captured more of the business by buying a same-sized company, Simstar, a digital ad agency with $10 million in revenue.

In 2007 he found a private equity partner, Lindsay Goldberg, to fund Rosetta’s buildout. Since then Rosetta has acquired Cleveland-based Brulant, a software company that partnered with IBM, and, just announced last month, Wishbone, a healthcare strategy and communications firm.

A caution for today’s economy: “We couldn’t have done the Simstar acquisition – borrowing $4 to $5 million on a $20 million company – today.”