The number of Chinese bloggers more than doubled during the first nine months of the year, driven primarily through aggressive marketing and product development by service providers, a research firm said Friday.

As of the end of the third quarter, there were 33.4 million registered bloggers in China, compared with 14.75 million at the end of last year, Analysys International, a private Chinese market researcher said.

China's blog market is evolving from the marketing phase to one of rapid growth, the firm said. To drive the market, blog service providers and large portals, such as Sino Blog and Microsoft Corp.'s MSN Spaces, are aggressively developing and launching new products and services.

Most bloggers subscribe to free services, but there's also a demand for paid VIP and mobile blogging services.

The top three blog service providers in the third quarter were Q-zone of QQ, Buluo of Netease and Blogcn.

Blogging in general is particularly popular with teenagers and young adults, who make up the majority of Internet users in China. The typical Chinese on the Web is under 30 years old, according to a study by the Chinese Academy of Social Sciences in Beijing, a government think tank.

A Chinese Academy survey found that 80 percent of people 24 years old or younger use the Internet, and 60 percent to 80 percent of people 25 years old to 29 years old. Fully 77 percent were single people.

China has the world's second largest Internet population, experts say.