China has not only the largest online population but also the most involved users. Almost half this population is mobile only (1).
There are multiple reasons for high involvement including:
Age of the Population:
The Internet population is younger in China than in the United States and Europe.
Way of Life:
Some people see the online world like a private area where they can affirm their individuality and have a second life.
Other people eat outside and feel the need to be in contact with their closed relatives: friends, family and even colleagues.
OnDevice Research, March 2012, URL: http://www.slideshare.net/OnDevice/post-pc-erathe-mobile-only-internet-generation-china