Interesting that almost none of these devices are shipped with Google Account integration. What does Google get out of this huge market share?
More interesting (for Google) is that 90% of Chinese people don't buy Windows and iOS phones.
Opensource at its finest and opensource as a defence weapon at the same time.
70% of people in the west doesn't buy Windows (nobody buys Windows phones, period), or iOS phones anyway.
So, it's not much surprise that Android does well in a much poorer market. It always catered mostly to the lower end of the market in the west too.
A larger ecosystem. People writing android programs for the Chinese market will probably also upload them to Google's stores.
I'm sure lots of the programs will be junk and/or uninteresting in other countries, but the better programs will probably be able to afford localization.
Don't bet on it. Most of those will be highly localized, and those people, mainly Chinese, would have to jump through hoops to get them on Google stores for not much benefit.
In fact, Google does not make much, if anything at all from the whole Android thing, Samsung makes a killing though.