With over 280 million registered users, Sina Corporation (新浪公司) (Nasdaq: SINA) is the largest online Chinese community in the world.   The company's main services are its web portal, Sina.com, and its microblog site, Weibo.com. The company's main revenue stream is advertising sales on its web portals (sites offering aggregated local news, entertainment, sports, etc. content). The company also sells mobile phone applications, ringtones, and other content to mobile phone users. Although the company's main audience is in mainland China, it also delivers local content to Chinese communities in Taiwan, Hong Kong, and North America.
With an already sizable community, Sina is well positioned to take advantage of the of the growing popularity of Web 2.0 and has begun to focus on user generated content. Sina Blog grew tenfold in the past year, and during the same time, the company launched Sina Podcasting, a service similar to You-Tube that lets users to upload videos. These efforts contributed to a 10% increase in revenues to $212.9 million with online advertising revenues increasing 44%.(Read more at Wikinvest )