Store closures a sign of the times.

"Going out of business" signs have not been so scarce in New York City this year, with stores such as Tower Records, Coliseum Books and even some Gap stores closing up.

But Big Apple brokers aren't worried because the market looks to be following a trend of "natural selection"; whenever one store closes, two newer and better stores open up, and shoppers keep on shopping.

"The reason certain stores have closed or are closing is not an indication that the retail market is bad, it is an indication that technology has improved and that styles have changed," said Jeffrey Roseman, executive vice president and principal of Newmark Knight Frank.

"Tower Records has gone out of business but Apple stores keep expanding because these stores are more in tune with what is going on today. Once the automobile was invented, horse and carriage went out of business."

Some closing stores aren't just outdated, they're finding it hard to keep up with the city's ever-increasing rents.

According to the latest numbers from the Real Estate Board of New York, as the median price per square foot climbed 12.5% from the same period last year. Ground floor median asking rent on Madison Avenue currently stands at $1000 psf while on Fifth Avenue in the Flatiron District, median prices climbed 28% to $263 psf.

Rents on Seventh Avenue in Midtown have risen 42% since last year to $479 psf and the price per square foot on West 42nd Street soared to $300.

According to Cory Zelnik, president and CEO of Zelnick and Company, New York City continues to enjoy a healthy economy and many of its permanent residents are earning top dollar.

"People have money and they want to spend it," said Zelnick, who recently launched his own firm. "Whether people work here, live here or are just visiting, these bodies mean shoppers, and that's what makes landlords ask for such high rents, and what makes retailers willing to pay it."

Many stores that don't shy away from the rental rates stay simply for the branding effect that only New York City has to offer. Just being displayed on the streets of New York is enough for many national and international retailers, according to Richard Hodos, founder and principal of Madison HGCD, LLC. "The main concern of these stores is not to make money."

Although the retail market overall has been vibrant, the luxury end has provided the extra boost, with Gucci, Fendi and Prada all doing extremely well, according to Robin Abrams, executive vice president of Lansco Corp., and chair of the REBNY Retail Committee.

"Luxury tenants have continued to expand in areas such as Soho and Herald Square, and Hermes and Tiffany's have opened up shops downtown, while new areas like the Meatpacking District continue to evolve," said Abrams.

The luxury brands have caused a space crunch on Madison Avenue where there has been a scramble to open stores in recent years. "Who would have thought a few years back that the luxury market would be doing so well," said Deborah Jackson, executive managing director at appraisal and accounting firm, Weiser, LLP. "There is a thirst for merchandise like Burberry and Dior that extends beyond the wealthy. Nowadays, girls will save up all their money to buy a $900 dollar Prada bag."

With the holiday season on the horizon, retail is only beginning to bloom and there are plenty of new products being introduced to keep consumers shopping well into the New Year.

"We're approaching a very strong holiday season, which I believe will be stronger then last year, because people have already begun shopping. The number of leases and property that we control is at an all-time high, because the amount of sales that can be done is higher then anywhere in the country," said Faith Hope Consolo, chairman, of the retail leasing and sales division at Prudential Douglas Elliman.

"Shops can close, but as long as the economy is good consumers will keep shopping," added Roseman. "If Abercrombie & Finch or Starbucks started closing, then I would be nervous."