Southampton, N.Y. ALESSANDRA CANARIO approached the restaurant table, her eyes as round as pie tins. Turning to her younger sister, she hissed: “That’s Michael Kors, Sabrina, don’t you know? He’s that guy on TV.”

Seated at Sant Ambroeus on Main Street here, not far from his weekend home, Mr. Kors glanced up and greeted the girls as genially as if they had been favorite nieces. “Oh, we’re soooo sorry,” Alessandra murmured, embarrassed to have interrupted the designer’s lunch. “It’s just that we are such big fans of ‘Project Runway.’ ”

For Mr. Kors, who made his debut two years ago as a judge on the fashion reality show, encounters with fans who know him more as a personality than a designer have become routine.

Each week his improbably pink, cherubic face beams from the home screens of cable-television viewers. He ladles out encouragement to aspiring designers like chicken soup, occasionally seasoning his homey brew with a stinging put-down. “One of my aunts might have worn that dress,” he recently told a young hopeful. “It’s, like, a good bar mitzvah moment.”

The folksy wit and fastidious eye that are central to his charm are the legacies of Mr. Kors’s upbringing in another Long Island, suburban Merrick, N.Y., where, he likes to say, his mother, Joan Kors, encouraged him to sketch and lent him her style gene. In his mother’s fashion prime, the ’70s, “she wore hot pants and lace palazzo pants,” he says. “We were competing for fashion victimhood.”

Mr. Kors’s signature — as a designer and a personality — derives partly from the contradictory desires to escape that past and to embrace it. His fashions display an infatuation with the traditionalism of the Eastern Seaboard haute bourgeoisie. Yet he also likes to tweak it for customers who want to look polished and prosperous but hip. In person Mr. Kors makes a near fetish of affecting a patrician ease, but he cannot resist the self-deprecating quip.

His knack for catering to clients’ fantasies — and his mounting visibility — have combined to transform his once modest business into a fashion brand with more than $600 million in wholesale revenues and 60 stores.

“Michael is firing on all cylinders,” said Terry J. Lundgren, the chief executive of Macy’s Inc., the parent company of Macy’s and Bloomingdale’s, where sales of the designer’s sportswear and accessories have surged. “This is his moment.”

Mr. Kors, 49, a presence in American fashion for nearly three decades, views such pronouncements skeptically. “My moment? Well, I’ve had a few,” he said.

As fall approaches, his image and imprint seem to be everywhere. The models in his new advertising campaign look icily confident wearing Mr. Kors’s cat spots and mink. His spring 2009 collection, inspired by ’50s Portofino and ’60s Malibu, will be unveiled in its usual Wednesday morning slot during New York Fashion Week next month, on Sept. 10. Later in the month, he will make a cameo appearance as himself in “Gossip Girl,” playing to the children and grandchildren of the women who discovered his sporty brand of glamour in the early 1980s.

His pop currency derives directly from “Project Runway,” now in its fifth season on Bravo (it will move to the Lifetime network next year, lured by a better offer). Mr. Kors is a vital attraction, alternately boyish and avuncular. “He is funny and opinionated, but genuine,” said Harvey Weinstein, the executive producer of the show. “People believe in his integrity.”

Mr. Kors is a “highly marketable personality,” said Milton Pedraza, the chief executive of the Luxury Institute, a market research company, adding, “The show makes Michael Kors seem current in a way that really captures the next generation.”

Certainly, it has given him an edge among younger celebrities, society figures and their followers, who think of him as a groovy alternative to Oscar de la Renta. His oh-so-proper sheaths, inspired this season by the polished style of “Mad Men,” have been embraced by surprisingly disparate personalities. “You think to yourself,” Mr. Kors marveled, “This is the very same dress that is hanging in the closet of Jessica Simpson and Barbara Walters.”

A source close to the Kors company said that the designer’s “Project Runway” fame has translated into 5 percent of the company’s gross. “No question it helps that Michael is a media star,” said John Idol, the chief executive of the Kors company, declining to confirm an exact figure attributable to the show. “Project Runway has had a major positive effect on our business.”

Since 2003, when his company was sold to Silas Chou and Lawrence Stroll, former investors in Asprey, the British jeweler, with Mr. Kors retaining a sizable share, the brand has benefited from financial muscle.

Once chiefly a clothing brand, the line now includes handbags, shoes and other accessories (accounting for 85 percent of sales). In addition to the top-tier designer collection, priced from about $700 for a sweater to around $3,000 for a cocktail dress, there are two lower-priced women’s lines, Michael Michael Kors and Kors Michael Kors (shoes and coats), and a men’s wear label.

The lines, sold in department stores including Nordstrom, Lord & Taylor and Neiman Marcus, are also found at 31 free-standing Michael Kors “lifestyle” shops. An additional 70 of those stores, which sell both his high-end and secondary lines, are planned over the next three years.. Next year the company plans to increase its advertising budget by 15 to 20 percent.

“We are on a fast track,” said Mr. Idol, a veteran of the Donna Karan and Polo Ralph Lauren companies. He projects that within three years the Michael Kors brand will reach $1 billion in sales in the United States alone, putting it in the company of CK Calvin Klein and Liz Claiborne.

At Bergdorf Goodman in Manhattan, where Mr. Kors’s top-of-the line cashmeres and sexy stenographers’ skirts hang alongside versions by Prada, Jil Sander and Narciso Rodriguez, sales have jumped by more than 50 percent in three years, Jim Gold, the store’s chief executive, said. “He is one of our most important designers.”

Mr. Gold pointed out that the brand owes much of its success to Mr. Kors’s mix of media savvy and a pragmatic approach to business. Mr. Gold said: “He spends time on the selling floor. He knows the sales associates. He knows our merchants. He doesn’t operate above it all, he rolls up his sleeves and digs in.”

And he knows his customers, befriending them at trunk shows, escorting them to industry galas, and firing their enthusiasm by blending the outrageous with the staid.

“His clothes are clean,” said Bette Midler, a client and longtime friend. “But they have that little bit of edge. He’s quite fearless in his use of gilt and glitter.”

Paul Cavaco, the creative director of Allure magazine and a stylist for past Kors ad campaigns added, “His clothes are chic but not neurotic.”

Mr. Kors makes no secret of having survived bleaker times. The grunge ’90s were unkind to him, and the departure of an important investor at the time nearly forced him to close. “Being in Chapter 11 was not fun,” he recalled. “Up until then I’d never even thought about failure, and all of a sudden it was like ‘deal with this.’ ”

Privately, retailers have disparaged Mr. Kors’s insistently conservative bent. At Saks Fifth Avenue, his label has picked up steam, said Michael Fink, the fashion director. But his quintessentially American sportswear, once shown alongside progressive labels like Comme des Garçons, have been moved to the second floor, placing him in the company of more traditional and commercial brands.

At the same time, the fashion press has sometimes chided Mr. Kors for overreaching. His collection for fall 2000, which attempted to resuscitate classic Bill Blass style with hourglass lines and ladies-who-lunch hauteur, was a critical flop.

Those memories may smart, but outwardly Mr. Kors is unflappable. Even in seasons of stinging reviews and heavy retail markdowns, loyal merchants have sustained him, he recalled, adding with some flint, “I never had a season where I didn’t show or didn’t ship.”

He is quick to acknowledge his enduring fascination with the touchstones of upper-class American style: haute hippies, Fellini-era jet-setters, Park Avenue royalty. During lunch in Southampton, he made reference to Ethel Walker, a Connecticut boarding school that is, in his words, “like Miss Porter’s but more discreet.”

“I tried to get in,” he said, deadpan. “But I was a boy and I was Jewish. It wasn’t going to happen.”