Though the English-language interface is still only partial, it will help turn the site into an important marketing tool for overseas brands and celebrities hoping to reach Chinese consumers, especially since there may be as few as just 18,000 active Twitter users in the country due to the fact that it has been blocked on the mainland since 2009. Having English capabilities will also help Sina Weibo ward off competition from rival Tencent Weibo, which added an English interface back in September 2011.
via Chinese Microblogging Giant Sina Weibo Adds English-Language Interface | TechCrunch.
