Returning travelers typically rush through the airport as fast as they can. Then there’s Yan Xue. She lingers in Beijing Capital International Airport long enough to load up on duty-free cosmetics.

The creams and moisturizers are as much as 30 percent cheaper than in town. Plus “shopping at the airport is convenient,” said Yan, 34, a project manager who had just arrived from a business trip to South Korea.

Yan represents an increasingly attractive customer for purveyors of cosmetics and fashion: middle-class globetrotters from China, Brazil, Russia and other emerging markets who see airports as malls — not to mention places where they can buy stuff that may be unavailable at home.

Companies such as Estee Lauder, Salvatore Ferragamo Italia and Burberry have pounced on the opportunity. Estee Lauder, for one, is hiring airport salespeople who are fluent in Mandarin, Portuguese and Russian, and trained to respect their customers’ cultural proclivities.

“We don’t sit on our hands and wait for today’s consumers to come,” said Olivier Bottrie, the company’s New York-based chief of travel retail. Airport-related sales rose about 24 percent in the first nine months of this year, he says.

Sales of fragrances and cosmetics at duty-free and other airport stores climbed 13 percent to $8.74 billion in the first nine months of 2010, according to Ornskoldsvik, Sweden-based Generation Research. Sales may reach $11.5 billion in 2010 and $12.9 billion in 2011, driven largely by Latin American and Asian travelers, the firm says.

Airports are the shopping “cathedrals of the 21st century,” said Michele Norsa, CEO of Salvatore Ferragamo Italia.

To make sure fliers worship at the house of Lauder, the New York-based company is working with travel sites to give tourists coupons they can print with their boarding passes. Estee Lauder put 13 percent more staff in its airport stores and is training them to understand cultural nuances — being more reserved toward Chinese shoppers, say, than Brazilians.

When passengers land from Shanghai or Beijing, Estee Lauder’s workers push eye make-up and moisturizers, popular items for Chinese travelers, to prominent spots. When flights arrive from Sao Paulo, they rotate the fragrances Brazilians favor up front.

About a quarter of the products sold at airport and duty- free shops were developed exclusively for those outlets, Bottrie said. Among them: Estee Lauder Super Flight Cream and a perfume called Adventurous.

To boost its airport sales in Asia, Coty’s Prestige division is introducing products tailored to Chinese tastes, such as miniature gift boxes and singer Gwen Stefani’s Harajuku Lovers dolls. The world’s largest maker of fragrances is also introducing merchandise at airports in such Chinese “out skirt” cities as Chengdu, Guangzhou, Xiamen and Qingdao.

The New York-based perfume company has added staff at key hubs such as Incheon in Korea, Shanghai Pudong and Beijing in China, Delhi and Mumbai in India, Taipei in Taiwan, and Changi in Singapore. Coty is also recruiting Chinese-speaking sales assistants in Korea and Singapore and increasing the frequency of product training in Asia.

“People are buying more,” said Coty Prestige President Michele Scannavini, who says Coty’s airport visits rose almost 10 percent in October, much of it driven by Asian travelers. “The Chinese are traveling a lot, and we think they are among the top two or three population in terms of purchase of duty-free worldwide now.”

Travel retail accounts for almost 15 percent of Coty Prestige sales, Scannavini says.

Other luxury-goods sellers are seeing similar trends.

Burberry’s travel retail business in Asia is performing “very strongly, driven by Chinese customers,” Pascal Perrier, who heads the luxury company’s business in the region, said on a conference call last month. London-based Burberry introduced a cosmetics line in July.

Shoemaker Ferragamo recently opened a store at Beijing airport, where sales are double forecasts, Norsa said.

“Asians are very much oriented to sales in the airports and also onboard,” Norsa said. “People also spend more time in the airport than in Europe.”