Recently we discovered that Google AdSense has only reach of about 2.2 million users. I believe china has over 2 billion population which is about 10% reach through Google's adwords.
Reasons are because China has it's own search engine called Baidu and most people use it. In China, people don't Google, they Baidu. They have something like 75% of the search market. So if you want to reach Chinese people, use Baidu.
1. China has it`s own search engine which they can control as they please
2. Google withdrew from China because of the country`s policy
There's also the fact that most of them don't speak English. Although according to source, about 200 million now speak it. But still, they are more likely to search on Baidu in Chinese. That's what
the 2.2 million number is reflecting, those using Google in English.
Google already withdraw out from China due to country policy. Basically local people unable to use google products as it was blocked. I believe the traffic you receive are those who are using VPN to promote in China, better look for baidu.