Don't forget to take into account land mass. The US is the third largest, while China is the forth largest. With the thought that, the smaller area there is to cover, the easier it is to connect your citizens. So, we have a 14% higher boadband usage AND a larger land mass, therefore, I think we are well not to consider this any pressing news.

Data gathered from:
http://cia.gov/cia/publications/factbook/geos/us.h tml [cia.gov]
http://cia.gov/cia/publications/factbook/geos/ch.h tml [cia.gov]