Social media is seen as a must-have channel for marketing in China. But China's "go-to" platform, Sina Weibo, is losing traction, especially for commercial purposes. WeChat, the current social media favorite, has many restrictions for commercial promotion. Meanwhile, Tmall has its own social medium, WeiTao, which Chinese consumers use specifically for social e-commerce. Here's a closer look at China's ideal channel for focused social marketing.