China is either the first or second largest world economy based on how you want to measure. It's rapid growth alone will assure Chinese economic power if not outright hegemony for the next century. China is also growing it's sphere of influence. Google is a corporation like any other, and if it misses the boat on getting into the Chinese market while it is still developing, it could be the Sears of search tomorrow.

Rich nations get rich by developing their economies. I don't think anyone has done that better than China. The US economy is exporting soybeans and shuffling debt. Who produces all of the high technology and is constantly innovating in the energy sector of tomorrow? China has seized the commanding heights of the economy.

But yeah, really, the world's biggest market is vital for Google.