"Rodeo has the true uberluxury type of consumer that typically only shops there and spends lots of dollars, and Rodeo also has the other audience that is heavily tourist based," he said. "Robertson is a younger audience. It is trendier. It is getting a lot of press."

Indeed, Robertson Boulevard's cachet appears undiminished even as the challenges of the broader economy — the housing slump, high fuel prices and tight credit — continue to weed out some boutiques that are relative newcomers to Los Angeles.

"Our Robertson store continues to surpass expectations. It is one of our top retail stores and has been very successful since we opened and is one of our top performers overall. Our continued retail expansion in California — in South Coast Plaza, and in San Diego and Malibu in 2008 — is in large part due to the success of this store," said Tory Burch.

For luxury "Robertson is a street to watch," said Robert Cohen, executive vice president of the retail leasing, investment sales and consulting firm RKF. "With brands like D&G and Chanel coming in, it is going to explode and rents are going to go through the roof. That's what's missing on Rodeo Drive, quite frankly. Rodeo is a beautiful street but...it is about the tourist."Cohen pointed to the precedent of Chanel opening a location in Manhattan's SoHo in 2002 selling apparel and cosmetics aimed at youthful consumers. "They were admittedly trying to get a younger customer,'' he said. "It was the clear motive. It's all about repositioning your brand."

Rents on Robertson are $20 to $25 a square foot, a range that has more than doubled in the last two years, compared with Rodeo Drive at $30 to $45; Melrose Place, $15 to $18, and Melrose Avenue, $8 to $15.

Jay Luchs, senior vice president of CB Richard Ellis, said turnover on Robertson amounts to only about three leases a year.

Higher rents are the inevitable result of increasing numbers of deep-pocketed tenants who end up edging out some smaller, independent retailers who may have been pioneers when the street was just starting to gain traction.