Chinese search engine service provider Baidu.com (BIDU) is reported in local media to be secretly acquiring some traditional advertisement companies to enhance its controlling power over ad sales in China.

With the growing of its market share, Baidu has gained a dominant position in the Chinese Internet search field and ad sales has accounted for about 80% of the company's total income.

All the companies that Baidu has acquired this time were its ad agents in the past and they can possibly bring more cost-effective sales channels for Baidu. Acquiring these companies might be the most effective way for Baidu to lower its costs and achieve maximum economic benefit.

Baidu is reportedly setting up a direct sales channel by combing these companies and their sales departments.