Sogou, the Internet service provider of Sohu, recorded $70 million in the fourth quarter of 2013, a 72% year-over-year increase or 23% quarter-over-quarter growth. 91%, $64 million, is from search advertising.

It’s the first quarter after Sogou announced to introduce strategic investment from Tencent and take over Soso, the search brand built by the latter. Soso employees and services have been integrated into Sogou in the following quarter.

Sogou + Soso had a combined 13.14% market share in December 2013, according to online data service CNZZ. In the same quarter, Baidu’s share and Qihoo’s are 60.47% and 23.1%, respectively.

Wang Xiaochuan, CEO of Sogou, said there’s synergy between the two search services that the majority of traffic on Soso, opposite from Sogou, is from mobile. Although Soso’s market share, 0.37%, is minor, Wang said they’d take advantage of Soso’s knowledge on mobile search.

Mobile search contributed more than 10% of Sosou’s total revenues, up from 3% for the previous quarter. Baidu first saw 10% of revenues coming from mobile in the second quarter of 2013.

Sogou generated $216 million in revenue in 2013 and that’s a 65% growth.