Shanghai based AdChina (http://www.adchina.com/) runs the largest online Ad network in China. Industry expert estimated it has about 50% of the market share. As mobile internet becoming more mature, it is also entering the mobile space. Recently, it has allowed its advertisers to put their ads on WAP sites, via its network.
This puts it into direct competition with Shanghai based Madhouse (http://www.madhouse.cn), which runs the leading mobile ad network at the moment. Madhouse covers most of the leading WAP sites in China and it has a exclusive deal with Kongzhong as its advertising agent.
Madhouse also covers most of the mobile internet users in China. When I visited Madhouse in August, CEO Joshua Maa said, their network covered 145 million mobile internet users in China. At that time, total mobile users in China is only 233 million. That means they covered over 60% of mobile internet population in China.
It would be interesting to see how AdChina is going to battle with such as strong competitor.