Last year Baidu had over 80% of the Chinese search engine market. It is now under the psychological barrier of 70%. The 2013 market share figures are in the table below from CNZZ. Qihoo, shown in the table as 360 search, used free security products to capture a big audience.
Search Engine Market share in China: Qihoo 360 search is gaining significantly on Baidu. Click on table to enlarge.
They then added a search engine which now has over 15% of the market. This is a remarkable achievement in a short time. This strategy of first capturing market share and then adding search is what Facebook is trying to do in order to compete with Google. I am sure that Facebook is watching Qihoo carefully.