For the first time, over 10% of Baidu’s quarterly revenues was from the mobile, “roughly quadrupled over a year ago”, Robin Li, Baidu CEO, disclosed at the Q213 earnings conference call today. Mobile search traffic is mainly driven by Baidu search app and Baidu mobile browser.

The mobile bidding system was integrated into Phoenix Nest, Baidu’s bidding system for PC, in the quarter. The mobile version, however, isn’t so different from that for PC, offering advertisers features such as click-to-call and click-to-chat. Robin Li said they’d offer more such as geo-targeting and click-through rate prediction.

Baidu declined to answer questions on the planned acquisition of NetDragon’s 91 Wireless but disclosed that mobile app distribution through search and Baidu’s app store increased more than five times year-over-year in the quarter. It has made some revenue through app distribution — mainly from mobile games.

The company recorded $1.228 billion in online advertising revenue, a 38.3% increase year-over-year. Active advertisers were 468 thousand, a 33.0% increase.

Traffic acquisition cost, revenues shared to third-party web services on Baidu’s contextual ad program, as a percentage has increased to 11% from 8% one year ago. The company attributes it to “increased contextual ads contributions and hao123 promotions.” Which means the search marketing revenue from its own search site and services didn’t grow so fast. Qihoo, the rising competitor in search to Baidu, has gained 16% in search market share while Baidu’s has declined to 66%, according to CNZZ, a third-party statistics service.

Baidu claims it has had the biggest online video platform and the most popular map service in China. After PPS, a P2P video service was acquired and became a subsidiary of iQiyi in last quarter, Baidu believes it has become No. 1 in terms of mobile users — thanks to PPS — and video viewing time. A cited report by CNNIC survey shows 40% Chinese users choose Baidu mobile apps over others, ranked No.1 while the second largest provider has a 23% share.