Domain name or domain number?
As I observed some of the famous websites in China, there are a tendency of using number in their domain name. Some notable sites in China, e.g. China’s first search engine, i.e. 3721.com; a famous China social networking site, i.e. 51.com, and my favorite sites in China, i.e. hao123.net and 163.com, they all have numbers in their domain name.
I wonder this is due to cultural or language (pronoun) localization? Or all these site owners tend to believe using numbering technique in their sites, their sites would get a better ranking in China’s search engine such as Baidu.com or Qihoo.com?

