Some more solutions:
Phone & SMS billing in non credit card countries, do the same for your credit card declines, setup is pretty easy in both NATS & MPA3 to GeoIP target your billers
Translate sites into multiple languages, especially french, spanish, german, portugeese,russian is carrying a big % of the overall surfers, chineese as well.
Dont forget that porn consumers buy porn from all over the world, not just US and Europe, especially russia is growing FAST
A lot of chineese surfers consider porn a kind of art, with the right content you will do very well, especially cartoon type of porn is big in china (since hardcore is illegal)