There's a business maxim that's been around as long as the world's oldest profession: Sex sells. These days it rings as true as ever, particularly in Chicago. "We want our guys to look as good as possible," says Sarah Blessing, co-owner of Apartment Number 9, a Chicago menswear store manned exclusively by women—young, attractive women at that.

The string of satisfied male clients coming and going might suggest a more illicit enterprise, but this Bucktown boutique is a wholesome family establishment, founded six years ago by Sarah and her sister Amy. (Even Mom Blessing's hand-knit cashmere hats and scarves are for sale.) Beyond the Etro and Martin Margiela hanging on the racks, the shop's biggest draw is the staff's expertise. While most wives and girlfriends are never lacking in unsolicited style advice, these ladies are actually trained to help men become smarter dressers.

I sampled their top-drawer service myself on a recent weekend when my wife and I unexpectedly secured a table at Alinea, chef Grant Achatz's molecular-gastronomy mecca. The only problem: I was without a suitable pair of pants. If a jacket and tie were required, I thought it a safe bet that denim would be fabric non grata.

As Sarah asks what I'm looking for, her eyes keep darting down to my clothes. But not in a judgmental way. It's more like being inspected by a gifted appraiser. Within minutes, and without any hints, she decodes my outfit: Seize sur Vingt shirt, Unis sweater, Ralph Lauren sports jacket. Racing through options, Sarah says, "It's really all about the fit. You're a 34-inch inseam, right?" Spot on—this is like a carnival act. My wife, who knows a thing or two about fashion herself, offers me a pair of Dries Van Noten trousers. Sarah, with the diplomatic skill of an ambassador, acknowledges the suggestion but instead hands me a pair of gray Paul Smith pants, saying, "These will look great, though I'm afraid they might be a little short." She's right, so then she's off to the tailor next door, and within a half-hour I'm properly outfitted for dinner. Incredibly, everyone is satisfied, my wife and Alinea's maître d' included. It's no wonder that over the years Sarah has become friendly with many of her customers. Yet there are some downfalls to catering to a strictly male clientele. "Thank God the Bears season is over," Sarah moans, explaining that during the team's prolonged run last winter the shop was not its usual busy self. "I was like, 'They're in the Super Bowl now? Come on!' "—MICHAEL MRAZ

digg this | add to del.icio.us | add to reddit

[To discuss this article—or to comment on anything in the magazine or on mensvogue.com—visit the Men's Vogue Forum.]