Everton and Man City have both tried the Chinese Market.. in Everton's case it just rose to a rise in the number of unofficial replica shirts.
We signed Li Tie and Li Weifeng, whilst Man City signed Sun Jihai. Apparently Everton v Man City was the most watched game in the Premier League of all time because of those players.
EDIT - Also, we had Kejian, a Chinese phone manufacturer who did not sell in the UK as a shirt sponsor.