The world's largest sock factory is also located in this town, producing 1.5 million pairs of socks a day.

Similarly, Yiwu has the world's largest jewelry industry that creates a daily average of 200 new styles of fashion accessories for domestic and overseas markets.

Wang Shibing, a migrant from Handan, Hebei province, came to Yiwu in 2006 to establish a household products factory, which now has annual sales in excess of 100 million yuan.

A shopper from overseas looks at wares in the mart. [Han Chuanhao/Xinhua]

He says that coming to Yiwu was one of the smartest business decisions he has ever made.

"Doing business here is so convenient and easy," he says.

To start a business in Yiwu, "all you need to do is rent a place, buy some desks and chairs and think of a name for your company. Besides, it offers an astonishingly wide selection of goods and an unparalleled, convenient transportation system", Wang says.

According to Xu Chunhui, vice-director of the city's Urban Planning Bureau, there is another 12.5-sq-km Trade Mart under construction at the west side of the city. It will be dedicated to the trade in "professional tools and equipment".

"We will divide the Mart into more specialized zones and try to keep the increase in stall rentals to a minimum," Xu says.

The expansion of the Trade Mart, however, is no longer within the city, or even in the country. On Jan 5, Zhejiang China Commodities City Group Co, the owner and the manager of Yiwu Mart, announced that it will build a 2-million-sq-m project, the size of 100 football fields, in Bangkok, Thailand.

The Bangkok version of Yiwu's Mart, expected to be completed by the end of 2013, will be able to accommodate 70,000 stores mainly selling commodities made in Yiwu and provide 160,000 jobs for the locals.