“Some clients demand mediocrity and will settle for nothing less,” Pat Fallon says.

Those who know him only by reputation might file that witticism under “Fallon, brash.” But the co-founder of Fallon Worldwide, the advertising agency that arguably put Minneapolis on the international marketing map, is no Mad Man. He’s Midwest mellow as he sits in the agency’s mod conference room on the 24th floor of the AT&T Tower in downtown Minneapolis. That rep for brashness probably reached its height in the 1990s, when Fallon the man and Fallon the agency more than fulfilled their dreams of working for major national clients—without leaving modest Minneapolis.

It all began with a full-page “manifesto” that appeared in the Minneapolis Tribune in 1981. The co-founders of what was first called Fallon McElligott Rice threw down a challenge to what they saw as a tired industry. To Fallon, the dominant approach to advertising in those days was “media leverage”—buying hours of media time to “drill insipid jingles into people’s minds . . . . We thought that you shouldn’t have to shout 20 times to be heard once.”

Fallon and his comrades saw the opportunity for an agency focused on creative messages. What’s more, they wanted to be a national agency. “We all lived here,” Fallon says. “We didn’t understand why it couldn’t be done here.”

It has been done. Indeed, the agency now called Fallon Worldwide has offices in London and Tokyo. Back in 1981, the founders had ambition—and no clients. The first ones were mostly local, including Gold’n Plump chicken. A year after they started, Fallon and company pursued a pitch for Midway Airlines—which they lost to an established agency.

Afterward, a Minneapolis ad veteran took a crestfallen Fallon to lunch. “I told him that we made a brilliant pitch and we didn’t get it and I was a little discouraged about that,” Fallon recalls. “He kind of put his arm around me and said, ‘Why do you need to be a national agency? Why can’t you be satisfied with being like the rest of us?’

“And I thought, ‘I don’t even know how to respond to that question.’ It was like we spoke different languages.” In a paradoxical way, “he gave me encouragement.”

In 1984, Fallon McElligott Rice was named Advertising Age magazine’s Agency of the Year. “Once that happened, the Wall Street Journal hired us,” Fallon says. “And once the Wall Street Journal hired us, it became OK to take a chance on us.” And big brands did: Time. Rolling Stone. Porsche. Lee Jeans.

Though the agency’s own brand was built on clever, often comedic visual ideas, Fallon argues that successful campaigns require knowing consumers “in ways that no one else had gotten to know them.” Take Citibank, a client from 2000 to 2007. “Citibank was a big, empty vessel” in 2000, he recalls. “It didn’t mean anything to anybody.” Since it couldn’t base a campaign on product attributes, Fallon “found an audience that represented nearly 50 percent of consumers—they were really happy in their lives.

“We said: ‘We’re going to bring you a bank that knows that there’s more to life than money.’ ” The agency’s “Live Richly” work gave Citi something it needed—a brand identity.

Fallon is candid about the whiffs as well as the wins. In Juicing the Orange, a 2006 book he co-wrote with agency co-founder Fred Senn, Fallon discussed the late-’90s Miller Lite campaign designed to bring a younger, hipper market to the beer brand. But distributors loathed the often off-the-wall TV spots (in one, a group of beer-drinking cowboys in a bar sing “Adios, Amigo” as they amble slowly toward the men’s room). The campaign failed to sufficiently boost sales, and Miller and Fallon parted ways.

The Lite campaign might have missed the mark. But the series of films the agency produced for BMW in 2001 and 2002 blew the target away.

“We knew that [BMW’s] customers were very tech-savvy,” Fallon recalls. The agency proposed putting all of BMW’s media dollars into online films. “We’re not going to get everybody—we’re going to get people who are interested in BMW or interested in technology.” The eight 10-minute movies, starring Clive Owen, with major film and TV directors at the helm, earned BMW big sales boosts and abundant free publicity.

Besides creating strong campaigns, Fallon has spread talent throughout the industry. Pat Fallon “has had the single most influence on my career,” says Adam Tucker, president of Ogilvy New York and a Fallon account executive from 1995 to 2006. Fallon taught Tucker the importance of getting to know employees and customers. “I wouldn’t be running a large New York agency without having had that experience,” Tucker says.

Rob White, who worked at Fallon from 1992 to 2006 as planning director and then president, says that “one of the things that [Fallon] embodies is a constant push for ‘better.’ ” White, co-founder and CEO of innovative Minneapolis marketing agency Zeus Jones, says that mindset is “what I’ve tried to take forward into what we’re doing over here.”

In the past decade, Fallon Worldwide has had its challenges. Star creative director David Lubars left in 2004. The agency lost major clients, Including BMW and United, and key talent. Things started looking up when it bagged Cadillac in 2010—then looked down again when Caddy, which never warmed to the work, left last summer.

But Fallon thinks his firm now has its groove back. “We’ve won four of the last five new business pitches we’ve entered,” he says. For this renaissance, he credits Mike Buchner, a 30-year Fallon veteran who became CEO in 2011, and Jeff Kling, named creative director in July 2012. As chairman, Fallon walks the halls, steps into meetings, “making sure that I’m sensitive to the pulse of the agency. I’m kind of ‘Dad.’ ” He also oversees longtime clients Travelers and H&R Block.

Around Fallon HQ’s colorful entry area, the mostly young, casually garbed Fallonites project an air of hipsterly good cheer. Pat Fallon expects them to keep building his agency’s success, which he credits to the many talented people who’ve worked there. “Our original ownership complemented each other greatly. But we’ve had some great people along the way, and they’ve taken our vision and made it better.”