Since Cai Yi signed up for a microblog account two months ago, he has attracted about 30 followers, more than 20 of which are commercial users, and the same thing is happening to millions of China's microblog users.

Microblogs are no longer just a platform for self-expression, gossip and networking, they are becoming an increasingly fierce battlefield for businesses wanting to promote themselves.

Over the past year, microblogging has become wildly popular in China, with some 65 million China-based microblog accounts registered by the end of 2010 - and the number is growing by more than 10 million each month, according to the Data Center of the China Internet.

China's major web portals, such as Sina, Sohu and Tencent, have all started microblogging services.

As microblogging becomes increasingly popular in China, more and more companies are taking advantage of the service to broaden their business network and to build their brand.

At present, China's largest web portal Sina claims to have 5,000 company microblog users, including Starbucks, Chanel, and IKEA.

On the microblog pages of the companies, visitors can not only view advertisements, but also see consumer feedback and even commentaries on hot social issues.

An Internet surfer, -nicknamed Xiaoben, posted on his microblog page that he enjoyed drinking Pu'er tea, and within just 10 minutes, a microblogger who owned an online shop selling Pu'er tea wrote to Xiaoben recommending his shop.

E-commerce expert Lu Bowang says microblogging has opened a whole new dimension of marketing. Through microblogs, companies can quickly grasp the attention of potential customers and interact with them so as to build an intimate relationship, Lu said.

Further, a brand can be as easily damaged as established through microblogging, as consumers' negative feedback can quickly spread in the -online community.

Rules and regulations to supervise microblog marketing need to be established, and at the same time, business organizations need to enhance self-discipline and strive to build up an integrity-based business culture, Lu said.