In China, should you use a .com, a .cn or a .com.cn domain?
There is a common myth that using a .cn or .com.cn domain helps making your site more visible in China. This is just that, a myth. From a SEO (Search /engine Optimization) point of view, there is no specific advantage to be gained by using a .cn or .com.cn domain.
That said, one shouldn’t necessarily focus everything on SEO. The goal, after all, is to get people on your site, not search engines. If you are an international brand, and have a specific site, with specific services targeted for China, it does make sense to use a China-focused domain.
Then, what to choose, cn or .com.cn? There again, no technical advantage for either choice. It becomes more a matter of branding, or consistency between your other localized sites, if any. Some find .com.cn a bit confusing and prone to typos. In practice, we find it doesn’t lead to many issues.
It really is more a matter of marketing, taste, and consistency with your existing or planned developments.
On the technical point of view, it doesn’t make a difference.