For the partners at mono, it was never a matter of if, but when. As far back as 1994, when Chris Lange and Michael Hart formed their creative partnership at Cevette & Company in Minneapolis, they kicked around the idea of launching their own agency—a dream they maintained as their partnership moved to Mullen and then Carmichael Lynch. At the latter, they met account executive Jim Scott, who would soon become their co-founding partner. The trio continued talking—comparing notes about how they’d run a shop when the time came and, equally important, how they wouldn’t.

“There seemed to be a lot of hierarchy at the more traditional agencies,” says Lange. “We spent a lot of time trying to sell our ideas internally even before we got to the client. We wanted to create something different. We wanted to build a structure that was as stripped down and free of layers as possible.”

Lange and Hart were group creative directors at Fallon, Minneapolis, having added an Emmy and a Cannes Media Grand Prix to their already voluminous awards collection, when they got the chance. Sesame Workshop, producer of Sesame Street, called the creative team, which had previously worked on a side project for the brand. Were they interested in taking on more work? “I remember thinking, ‘This is it,’” says Lange. “‘This is the defining moment. If we’re not going to do this now, then we’re probably never going to do it.’”

It was, he adds, an easy decision. In January 2004, the three partners founded mono. Today, mono’s 23 employees are somewhat cramped in the office—a light and airy, renovated warehouse—by press time, they’ll have moved to a vastly larger space. Plus, there’s the trailer. In a pinch, the vintage Airstream, parked on the grass in a side yard, provides an additional meeting area. It sits next to a plastic flamingo, which Lange painted “mono blue,” the agency’s signature color.

But it’s more than just extra space. The backyard motor home commemorates an agency milestone: Airstream was the first account mono won after Sesame Street. Today, the agency’s roster includes Discovery Networks, TurboChef, Newman’s Own, PBS, OfficeMax, Harvard Business School, Herman Miller and Apple, while recognition has come from the Clios, the Webby Awards, The One Show, Cannes, I.D. magazine, Communication Arts and more.

That heavy-hitting list stems from mono’s unwillingness to compromise. The partners made an early decision to turn down clients who didn’t share their appetite for great work. Talking to the three co-founders about those early days, it quickly becomes clear they’d have built their client roster judiciously under any circumstances, but their capacity to do so increased dramatically when, four months after launching, MDC Partners acquired a minority ownership stake in mono.

Another milestone came early in the agency’s life, when mono won the USA Network account in a pitch against StrawberryFrog, Modernista! and taxi. “They asked for some great TV,” says Hart, who, with Lange, uses the title of creative director. “We said, ‘You need more than that.’” At the time, media buyers were struggling to see the relevance of the network—a hodgepodge of programming that ranged from the TV series Monk to wrestling and second-run movies.

During presentations, mono often throws up a slide that encapsulates its working philosophy: The future belongs to the simpleminded. “If we say that our strength is to help brands simplify,” says Scott, managing partner, “then this is exactly the kind of problem we want to solve.” From the patchwork of programming, mono extracted a powerful common thread: All of the network’s seemingly unrelated entertainment options center on characters—distinct, quirky, square-peg-in-round-hole characters.

Launched in 2005, mono’s “Characters Welcome” campaign celebrates those eccentrics, like Monk, TV’s only detective with OCD—shown in one commercial at the grocery store, neuroses on hilarious display. The agency also recognized an opportunity to engage the U.S.A. itself as a distinctly character-driven nation. Before YouTube became a household name, mono worked with interactive firm Hello Design to launch USA Network’s showusyourcharacter.com. More than 20,000 people registered to upload and view videos of the characters who populate America (think ventriloquist beauty queen, naked cowboy).

“It became clear that we could make this brand stand for something,” says Lange. “Not only from a marketing stand-point but in a way that changed their view of new programming and unified all its initiatives. And when you get to that point, brands can be extraordinarily successful.” After one year, Characters Welcome achieved an aided awareness of 75 percent, besting competitor tbs and its “Very Funny” line by a two-to-one margin.

The idea of standing for something comes up often at mono, and not just in terms of client problems. “Agencies are notorious for standing for nothing,” says T. Scott Major, interactive creative director. “Most don’t stand for anything other than what the leader at the time thinks great creative is about. Do they think great creative is art? Do they think it’s strategic? Some leaders don’t know what they think, so they jump from trend to trend. But mono stands for a philosophy. We say that we’re going to stand for simplicity—in our ideas and in the way we work.”

That shows up everywhere, even in mono’s color, which is process blue. According to one agency rule, mono’s creative briefs must fit on one page—and you can’t fudge the margins. There are also drastically fewer meetings here. In part, that’s because the issues that would be addressed around a conference table instead get hashed out at “the wall,” a simple bank of glass panes—and the most important feature of agency life.

As they work, creatives hang their concepts on the wall for their colleagues to view, providing a constant stream of feed-back. People leave notes: Why not do it this way? Impromptu meetings form. No one wastes time in pursuit of mediocre concepts. And others, inspired by the outside perspective, see new possibilities in ideas they’d otherwise have abandoned.

As a result, everyone—not just a few exalted creative leaders—feels a sense of ownership in the creative product. It’s not that mono is a commune of ideas. There’s no voting or consensus-taking. But the wall helps flatten layers and eliminate the territorial secrecy that impedes innovation in many agencies, where creatives hole up for weeks before unveiling concepts to a group of account people they’re prepared to fight.

Making it still tougher to work in silos is the structure of mono teams—usually composed of an art director, writer, interactive director, designer and planner or strategist. “It allows us to be truly media neutral,” says Hart. “Because that group of people will push around ideas in a way that a team of just a writer and art director couldn’t.” He’s quick to add that mono’s not opposed to a good, old-fashioned 30-second spot or magazine spread when appropriate: “But the playing field is much wider now. What we’re saying is that we want to be brilliant everywhere.”

And mono’s diverse body of work bears that out. The agency produces not just traditional advertising for Sesame Workshop, but extremely popular content for Sesame Street, a series of opening segments called “Word on the Street.” When Sesame Workshop launched its first “Word on the Street” podcast, it became the iTunes number-one video download in one week.

The partners are loath to label their shop. When pressed, however, they say they could live with branding agency. The fact that people have a hard time figuring out what to call mono (Is it an ad agency? A design firm?) makes the co-founders, die-hard media agnostics all three of them, very happy.

The design community is certainly paying attention; two judges at the 2008 AIGA Minnesota Design Show selected mono entries as personal favorites. And when mono launched monoface, a digital New Year’s greeting, blogs lit up with chatter about the cool, new interactive agency in Minneapolis. The microsite allows users to change the individual features of a photographed face—mixing a mustachioed mouth, for instance, with an otherwise female visage—creating about 750,000 magnificently freaky combinations. Sent initially to about 500 people, it spread fast—shutting down mono’s server in three days.

Digital pundits also lauded mono’s viral game for General Mills, “Food fight,” which drove traffic to the health information site EatBetterAmerica.com, a General Mills brand that mono built from the ground up. The game’s object: Hurl food at one of three opponents, who return the favor while talking some downright crazy smack and splattering virtual sauce across your screen.

For all the play, mono did serious work to position the brand strategically, helping General Mills see the value of distributing information without pushing product or loading up the site with logos. That earned more consumer respect than a hard-sell ever could. In the end, the project says as much about mono’s branding expertise as it does about its interactive capacities.

In a modern media landscape, when an agency’s success depends on its ability to solve brand problems across an ever-changing range of media platforms, mono is positioned for growth. The partners don’t have a precise size in mind, but one thing’s for sure: As mono expands, the wall will continue to shape the way ideas get produced. In fact, it will be the most prominent architectural feature in the new office—sitting in the middle of the space so that all foot traffic flows past it. “It’s a matter of putting the ideas at the center of the agency,” says Hart, “literally and figuratively—and making sure we keep them there.” ca