How different between Facebook and Kaixin

I am a daily user of two social networking websites: Facebook and Kaixin(kaixin001.com). Facebook is for networking with my Stanford friends, while Kaixin is for networking with my friends in China. Kaixin is said to be the copycat of facebook of China; however, it is not true just in terms of my behavior.

Difference 1: name.

I use real name on facebook, and all my friends use real name. However, I use fake name on Kaixin, while I know there are plenty of friends using fake name too(amazing we can still find each other)

Difference 2: activities
I usually look at the news feed on facebook to learn what my friends are doing: I leave msg to them, comment on the pictures, as well as upload photos; However, I don't often change my status on Kaixin, neither do my friends. I never have a profile photo there, and don't upload my vacation photos. I spend 90 % of the time on playing games with friends. We buy and sell each other, plant garden, and raise a lot of pigs, rabbits and cows as pets.

Difference 3: interactions with the site
I get plenty of msgs in my facebook account; I never communicate with facebook system. On kaixin, most of the message I get are from the systems, such as "your friend just bought you in 60000 dollars", or "you was just award 1000 dollars".

It will be some interesting research topic for academia on why such difference is generated. I am sure there is something related with different culture, or different user behavior. This may suggest that social networking website may have a hard time to expand globally. And there is always some opportunities for companies who work hard on learning local behavior.