Another company in the city, Shanghai Yunda Express Service Co Ltd, said it has set up a special "Singles' Day Working Group" to ensure deliveries remain uninterrupted, even when they peak on Sunday.

Zhou Baigen, its head of marketing, said the company has learned from experience and added another 120 routes across the country, controlled by its 70 distribution centers nationally.

Many vendors selling products that have nothing to do with the festival have also introduced "slow delivery" services, for less urgent deliveries, to help prevent delays.

Wary of the possible logjam, for example, Nippon Paint (China) Co Ltd has offered its customers the chance to order products sold on Tmall two months in advance, said He Xingan, its director of distribution in China.

Wang Ying said the delivery cycle on Tmall has been lengthened to seven days, giving more flexibility to delivery companies to better allocate resources.

And companies insist they will not be charging extra during the period.

State-owned China Post Group has also entered the online shopping fray by collaborating with Tmall's Singles' Day event for the first time.

The move comes as one of its units, China Postal Express & Logistics Co Ltd, which offers the EMS express services, plans an initial public offering, according to the IPO prospectus posted on the website of China Securities Regulatory Commission.

The 9.98 billion yuan it plans to raise from the listing will be used to buy vehicles, airplanes and equipment, as well as fund an expansion of its network, it said.

Meanwhile, a new delivery company, Beijing ZJS Express Co Ltd, has pledged to charge "no higher" than traditional leading players, as it makes its debut in the market, to coincide with this year's Singles' Day.

"Our company has neglected online shopping in the past," said vice-president Lu Guorong. "But we can't risk missing this opportunity."

hewei@chinadaily.com.cn

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