But the number of headquarters of ceramic companies has been increasing in Foshan. As many as 120 ceramic companies have set up their headquarters in the CCIH, Zhang says.

He estimates that another 60 to 80 companies will move their headquarters to the zone by October 2012.

"We don't produce in Foshan anymore but the whole supply chain of the industry, from raw materials to production machines and R&D talent still gather in Foshan. There's no better place than Foshan to develop the ceramic business," Zhang says, adding Foshan also has about 40 media outlets just covering the ceramic industry.

The aggregation of the ceramic industry in Foshan is the key reason for Niro Granite, a Malaysian porcelain tile producer, to set up its China headquarters in the city in 2008.

"We don't have this kind of huge complex for building materials in Malaysia. Apart from our company, there are many more companies in the same sector. Those who want to buy construction ceramics all know that there is no better place to find their ideal products in Asia than in Foshan," says Alan Tho, the finance and administration manager for Niro Granite China.

Tho says his Foshan show room is about 800 square meters, which is more than twice the size of the one in his company's global headquarters in Malaysia. "When potential customers want to check out products, we usually invite them to Foshan," he says.

"And they all want to come, because they can seldom find show rooms as big as those we have in Foshan. 'Amazing' is the word that frequently pops out of their mouths when they have a tour here," Tho says, adding many of his colleagues in Malaysia want his position in Foshan.

According to Tho, though his export-oriented company does not have any production facilities in China, the nation accounted for 40 percent of Niro Granite's global revenue of about 800 million yuan ($126 million, 94 million euros) in 2010.

"We have a list of a dozen of qualified ceramic tile suppliers in China and they all have operations near Foshan or agencies in the city, so it is easier for us to do business," he says.

However, the extreme aggregation of the ceramic industry in Foshan has its side effects. Chen Yanbin, chairman of Foshan-based ASGF Ceramics, says it is difficult to tell the identity of those who come to your door.

"They could be potential customers who want to do business with you, but they could also be competitors from other companies who just want to steal your design," he says.

Chen's company has more than 100 patents in ceramic tiles but he says when his company introduced a new product to market in 2004, there were at least 240 companies that copied his design.

Even outsiders in the ceramic industry can feel the intense competition in Foshan. Signs of "no photos" can be found in every ceramic show room in Foshan. Sales figures are seldom revealed because all the companies are in stiff competition with one another.