Most 2 letter .com domain have been acquired by Chinese people.
Why Chinese People prefer short domain so much?
Short is better! it is easier to remmeber,easier to type in,easier to spread in oral.
JD and MI are two examples to see how Chinese people choose in domain names.
JD start business with 360buy.com,It is not a good domain,this can be easy understanding,it don't have enough money at the begining,acquire a catchy domain is not the first priority.When well-funded it acquired the Pinyin domain JingDong.com,Yes,It is Pinyin,The most popular type of domain in China.but it's unlike other Pinyin (Baidu,Taobao,Weibo...) Jingdong is easily misspell，especially in South China，Jingdong or Jindong ？Many people don't know which one is correct.Finally, it upgraded its domain to JD.com for Millions of USD. The cost is expensive. But Richard Liu(the founder of Jing Dong) says it saved about $20 million in advertising expenses every year after using JD.com.
Another case is MI, though Leijun(The Founder of MI) acquired Xiaomi.com at the begining.The name XIAOMI is farely well in China,But when it expanding to the world,The name XIAOMI is a problem,Most foreigner don't know how to pronounce the world XIAOMI,XIAOMI is also not easy to remember for people don‘t know Pinyin,So upgrade the domain is a must.Then it acquired mi.com for $3.6 Million USD in 2014.