Distill the prevailing menswear style of the past few years--selvage denim, tweed, fitted shirts--and turn it into a physical space, and it would be Liquor Store, a cramped boutique in a former corner bar in Manhattan's Tribeca neighborhood. Inside, a vintage wooden bar lines one wall, with bottles of whiskey and gin sharing space with colorful sweaters, a case of old Rolex watches and money clips, and various books and obscure fashion magazines. A threadbare oriental rug covers the worn wood floor, and slim-cut suits and dress shirts hang from creaky armoires stuffed in the corners. A constant stream of impossibly chic downtown dwellers shuffle through the tight spaces between the clothes.

The store belongs, improbably, to a mass-market clothing giant: J.Crew. Back in 2008, chairman and CEO Mickey Drexler decided it was time to elevate the image of J.Crew's menswear offerings, then a collection of preppy basics generally tucked into the back of the J.Crew stores. He needed a way to position the new, more refined menswear collection and attract a new breed of style influencer.

Drexler turned to his friend Andy Spade, best known as one half of the husband-and-wife founding team of the Kate Spade and Jack Spade fashion brands. The Spades had cashed out of their business in 2006, and shortly afterward, Spade and longtime friend and colleague Anthony Sperduti, who had been an art director at Kate Spade and Jack Spade, started working on a variety of branding and art projects together, eventually creating their own branding studio, Partners & Spade.

The three men brainstormed and came up with the idea of a standalone store. Spade and Sperduti suggested putting it in the old bar. But rather than follow J.Crew's retail playbook, the three decided that there should be no brand signage. The shop would be known only by what it said on the old neon "liquor store" sign hanging from the building, a holdover from the space's pre-bar life. There would be curated exhibitions of paintings and photography in the dressing rooms. The merchandise would be a tightly edited selection of J.Crew's new premium offerings along with some of the brands Drexler was adding to the menswear mix, such as Barbour and Alden. It would be the kind of boutique that stylish men dream about, a hidden gem that might be written up in Monocle, only this one would sell the wares of a mass-market brand.

Liquor Store, the project that put Partners & Spade on the map.

Today, Liquor Store is one of J.Crew's most successful stores by sales per square foot, and the company has opened a dozen standalone men's shops.

Liquor Store was Partners & Spade's first piece of commercial client work, and it was a home run. In the ensuing six years, the firm has become one of the most influential (and imitated) branding shops in the business. Its projects span practically every medium: a personal shopping app for J.Crew, TV ads for Target, a magazine redesign for Condé Nast, and an entire brand-identity project for Canada's oldest retailer, Hudson's Bay. In each case, Spade and Sperduti have eschewed the idea that the best way to sell a product is to tell your customers what they should think about it. Instead, they believe that a brand should speak for itself through its interactions with customers. Those interactions, in turn, must be driven by an authentic and clear brand vision. The general idea, says Spade, is that no matter the size of your company, your brand should "act small."

A bag designed for Hudson's Bay Company.

Spade and Sperduti began developing this branding concept when they came together to work on a fledgling handbag company that Spade's then-girlfriend, Kate Brosnahan, was launching. A former magazine editor, she had designed a bag with clean, simple lines and an elegant sensibility that filled the gap between ostentatious luxury purses and uninspired functional bags. They named the company Kate Spade--Andy and Kate thought it had a better ring than Kate Brosnahan, even though the two weren't married yet. It was one of the earliest in a series of decisions that created what would become the iconic brand.

From the beginning, the partners focused on developing Kate Spade's identity--a complete brand instead of an ad campaign. "It was about this world we were creating, which was about graciousness," says Spade. "We built it around Kate's personality." Developing that identity involved making hundreds of decisions that don't seem to be about marketing or advertising, but in fact, are essential elements of both.

"We would talk about how to make decisions about, like, store location," says Spade. "What does it say if we're in SoHo? What does it say if we're on the Upper East Side? All of these things communicate something about the brand." They analyzed everything from the message on the answering machine to the color of the soap in the ladies' room. In addition to the handbags, the stores sold flowers and other unrelated products, some from other companies, to "round out the personality," Spade explains.

"It seems straightforward now, but back then no one thought like that," says Sperduti.

In 1997, about the time Kate Spade was becoming a major international brand, the Spades and Sperduti launched a complementary men's clothing and accessories brand, Jack Spade. The Jack personality was built around the idea of the creative boy-man, maybe someone who worked in an ad agency. Jack Spade products were sold in hardware stores for the first six months. But even as that brand took off, Spade realized he wanted to incubate more creative concepts and spend more time with his and Kate's new daughter. The Spades decided their growing company wasn't the best place from which to do either. In 2006, the Spades sold their remaining shares in the company to Neiman Marcus, which had purchased a majority stake in 1999.

Shortly afterward, Mickey Drexler called, and shortly after that, Partners & Spade was on the map.

A traditional branding agency might have parlayed the success of the J.Crew Liquor Store project into an aggressive round of pitching to other mass brands. Spade and Sperduti instead retreated to a downtown storefront and turned the front of the shop into a tour of their eccentric brains. They held art shows (vintage Playboy photography, a performance piece that involved someone providing free tax advice), published photo books with HarperCollins, and designed products, like hand-painted neckties, to sell on the weekends, when they opened their workspace as a store. If it all sounds like little more than creative self-indulgence, consider that in addition to being fun, every project was designed to make money or break even. More than that, the projects helped the partners refine their own brand.

"We've seen a significant shift in the way consumers embrace brands," says Kelly O'Keefe, professor of brand management and innovation at Virginia Commonwealth University's Brandcenter advertising school. "If you think back to the '90s, advertising was the tool for building brands. It worked by connecting brands to short messages or images. But it stopped working. We've had companies tell us one thing and do another. And what happens to us as consumers, when we feel like we've been lied to, is that we discount the message and look for deeper signals."

O'Keefe talks about brand behavior and brand touch as being more important than brand voice. "Amex can say they are all about small business, but there wasn't much reason to believe them before they launched Small Business Saturday," he says. "That's a physical manifestation of corporate behavior. It's not a message, it's an action--and that action shows intent. That's why we're seeing companies like Partners & Spade starting to make things that express brands more tangibly than messages alone."

When brands create a tangible experience for consumers, as Partners & Spade tries to do, those consumers walk away with material to share, in person and via social media, with friends and family. So each individual becomes a potential advertisement. Spade and Sperduti's work with online eyeglasses startup Warby Parker is a great example of how obsessing over details in order to bring a brand to life can become a powerful marketing and advertising strategy.

Warby's founders were deliberate in creating the brand identity even before Spade and Sperduti showed up; it's a kind of literary-inspired, conscientious cool. Partners & Spade helped Warby Parker stage live events, like a flash-mob eyewear fashion show at the New York Public Library, and create retail concepts, like a holiday pop-up shop in a pair of yurts erected inside an old garage in SoHo. After the holidays, Spade, Sperduti, and Warby CEO Neil Blumenthal decided to take the pop-up shop on the road, and they did it in a way that was uniquely Warby Parker.

"We started talking about doing a school bus," Spade remembers, "because obviously it's Warby, it's glasses, we're celebrating the literary life and learning." The idea turned into the Warby Parker Class Trip. They outfitted a school bus to look like an English professor's library, with oak bookshelves, old books and maps, and leather sofas. And, of course, a full selection of glasses and an optician station. The bus stayed yellow. Making it an overtly branded bus would have looked like marketing.

Warby Parker's mobile pop-up shop inside a customized school bus.

"Warby could have bought ads in Vogue and GQ, but we thought the bus was a more effective way to spend money for them, given their size and what they're doing," Spade says. Of course, all the fashion magazines published articles about the Class Trip, so that audience got the message anyway. Customers in 18 cities got to hang out with the brand. The bus interior was designed as a series of photogenic vignettes, so even more people saw the bus through the Instagram feeds of those customers. Blumenthal won't share the specific numbers about the Class Trip's return on investment, but he says the company saw meaningful lift in each of the metrics it tracked: press impressions, social-media impressions, brand perception, and sales. It was such a hit that Warby Parker kept the bus on the road for a year, instead of the planned six months.

Warby's SoHo store, which Spade and Sperduti worked on, was also explicitly designed to include Instagram-able scenes. A midcentury rosewood desk, with a sign above it that says "Eye Exams," shows up in photos frequently. The terrazzo floor has an inlaid Warby Parker logo that stars in a lot of snapshots. And the space is designed to enhance the social nature of shopping. A photo booth, to take shareable old-school selfies, and full-length mirrors replace the small, countertop mirrors used in traditional eyewear stores.

For the rollout of Shinola--a Detroit watch, leather goods, and bicycle maker and seller of American-made goods--Partners & Spade built the launch campaign around newspaper ads. Shinola's brand is about American manufacturing and a creative renaissance in a once-great city, and the ads were large documentary-style photos of American workers at work: machinery draped with a worn pair of gloves and a row of Midwestern-looking women at sewing machines.

Shinola's 2014 ads featuring photos by Bruce Weber.

"Because the company gets the behavior right, and the products themselves are beautiful, the ad role shifts from invention of story to, you put a camera on the behavior," says O'Keefe. "Firms like Partners & Spade are shifting the focus back to where it ought to be. It is very much the enlightened model for the future."

Like most successful concepts, the physical spaces and experiences Partners & Spade create are ripe for imitation. Marshal Cohen, chief industry analyst for analytics and consulting firm NPD Group, says that people "want something that feels customized or personalized, or they want to feel like they've found something special that other people don't have." He says that Partners & Spade was one of the first firms to design brand experiences that satisfied this customer desire. The challenge, he says, is that in retail, "as soon as something is successful, people copy it. For people who do the boutique business through merchandising, through adding lifestyle products that broaden the experience, through store design and leather sofas--all of that can be replicated." Cohen points to the in-store boutiques that have started popping up in stores such as JCPenney. "The idea starts to become a commodity even though the intent is to be separate," he adds.

Sperduti understands that imitators will imitate, but he believes that people will always recognize an original. "Business plans can be knocked off," he says, "but a unique brand cannot.

"There is the idea of having a narrative and concept and a level of wit built into the experience of the design," says Sperduti. "That doesn't have a shelf life. The aesthetics and style do have a shelf life. But the bigger notion of having an experience built on a narrative does not. We are constantly challenging ourselves to express those notions in new ways, because we believe all brands could use more of that."

Recently, Ivanka Trump came to Partners & Spade for help with her five-year-old fashion brand, which brought in an estimated $250 million in sales in 2013, according to projections last year from The New York Times. "I was able to grow a really sizable business in a short period of time," Trump says. "But I've never really taken a step back and tried to delineate and clearly and concisely say, This is what the brand is."

Trump wants Partners & Spade to help produce an experiential campaign for her growing empire. She's got a clear concept of what she wants her brand to be and she knows her target market. Now she needs help creating a clear brand identity, like Warby's, Shinola's, or Kate Spade's.

To Spade and Sperduti, having a clear brand concept is one of the most important preconditions for a company to be able to pull off an experiential campaign; otherwise, the brand behavior is just a stunt. Sperduti and Spade routinely turn away potential clients that lack it. "We've said a polite no more often than yes," Spade says.

Sleepy Jones, the firm's own loungewear collection.

Nevertheless, the firm is now up to 20 full-time employees. New clients include Etsy, Harry's razors, and Sephora, and, over the past year, Sperduti and Spade themselves. Partners & Spade is now launching its own brands from scratch. First up is a new apparel line called Sleepy Jones, men's and women's sleepwear and underwear that fills a niche between overly sexualized lingerie and functional, plain pajamas. J.Crew plans to begin selling Sleepy Jones products this spring. The next launch will probably be the first Kate Spade-branded hotel (the Spades retained the rights to create some brand extensions under the name).

As the firm grows and expands into more of its own projects, will Partners & Spade be able to take its own advice to "act small"? It's not likely that Sperduti and Spade will let it get to the point at which that's a problem.

"I said to myself a long time ago," says Spade, "that all these ideas that we have, if we really think that they're great ideas, let's find a place for them. Obviously, we have to be fiscally responsible, we have to pay our employees, we have to pay our overhead and all of that, but let's try to have this balance. Those things keep us excited."