Francois Bougon reports for AFP:
The 384 million people now online in China, where the need to build connections (guanxi) has always been vital, have fostered an explosion in web networking, led by instant messaging and video-sharing sites QQ and Youku.
But the government, wary of the power of such networks to quickly mobilise large groups of people, has blocked foreign sites such as Twitter on and off for months, which has guided Chinese users towards domestic firms, experts say.
"The Chinese government has been deliberately fostering domestic enterprises which are generally much easier to be controlled," said Xiao Qiang, who heads China Digital Times, a US-based site that monitors web developments in China.
"This is one of the essential components of the Chinese censorship mechanism, which also creates a trade barrier for the world's largest Internet market."
Twitter and Facebook were cut off nationwide in July amid deadly ethnic unrest in the restive far-western region of Xinjiang. Authorities blamed the spread of the violence in part on agitators who used the web to stoke it.