Chinese e-commerce company Alibaba.com has now officially launched Alimama, an online advertising exchange which allows web publishers and advertisers to trade online advertising inventory.

"No longer will 80% of China's website traffic go unmonetized," said Jin Jianhang, an Alibaba Group spokesperson. "The launch of Alimama makes web publishing commercially viable for China's more than one million small- and medium-sized web sites. At the same time, advertisers now have an affordable way to reach targeted audience groups on the growing number of specialized websites and blogs in China."

A wholly owned subsidiary of Alibaba Group, Alimama has emerged from its 100-day beta period as one of China's largest online advertising exchange platforms and is well positioned to help small and medium sized web publishers monetize the estimated 80% of web site traffic which goes unmonetized in China.

Alimama's business model is designed to meet the needs of China's fragmented market for online advertising, providing a system that is transparent to both web publishers and advertisers. To use the service, publishers register on Alimama.com to provide a description of the advertising inventory for sale, as well as the pricing models based on which the inventory can be sold, such as pricing based on impressions served, clicks or other actions by Internet users. Advertisers review the information posted by publishers, along with independent website traffic data.