'One out of three SMS [texts] sent in the world is sent by a Chinese,' said Mr Wang.

SMS has already had a profound impact on China. Last year the spread of information about the Sars outbreak by SMS helped force the government to admit the extent of the epidemic had been concealed.

Companies such as Tom Online are offering a host of news, games, dating services and other entertainment to the country's 269 million mobile phone users.

'Face-to-face contact was once considered important in Chinese society,' said Mr Wang. 'But today, many people prefer to send mobile messages.'

Though consumers in the major cities love to use SMS, it is really the large number of users in the smaller cities that are driving the growth in message volume.

'The lack of entertainment options in the second- and third-tier cities forces people to seek entertainment through their mobile phones,' said Mr Wang, whose firm earned US$19.6 million in net profit last year, most of which was derived from messaging services.

Other China internet portals, among them Sina.com, Sohu.com and Netease, earn significant revenue from SMS and other phone services. It costs only 0.3 yuan to send a text message.

Many SMS senders are in their teens or early 20s and spend an inordinate amount of time on the phone. SMS should also lead to a huge growth market for third-generation mobile phones once authorities approve a national 3G standard in the coming year or two.

Ringtones and pictures are the most popular downloads, but developers are quickly moving into three-dimensional products.

John Ho, general manager of US-based telecoms software firm Intergrafx, said his team was helping Chinese content developers design a host of 3D games and icons.

'People want to go beyond just text messaging,' he said. 'They want multimedia. They want 3D content. Once you view something in 3D, there is no way you want to go back to 2D any more. We see it as not just a market that will grow. It will explode.'

This year, Tom Online is accelerating the launch of interactive voice-response services and downloads of voice-activated products such as music, weather information and radio news.

'Many foreign companies complain they are losing money because of pirated VCDs or music CDs,' he said.

'But mobile interactive voice services offer these content providers a guarantee that they will generate income from their products. There is no piracy problem in mobile entertainment.'