Sina Weibo Launches Discussion Forums, No Longer Any 140-Character Limit

China’s hottest Twitter clone, Sina Weibo, has diversified yet again with the launch of a platform for BBS-like discussion forums. Called “Weiba” (see its homepage here), the forums are open to all 350 million registered Weibo users, and cover specialist topics such as IT, cartoons, the Olympics, and other more niche subjects.

The move by Sina (NASDAQ:SINA) is a challenge to the country’s biggest search engine, Baidu, which runs the popular Tieba discussions platform that Weiba is clearly emulating (not least in its name). It should help Sina to keep users around on the site for longer and give it yet more screen real estate on which to put ads.

Weiba has been in beta since the end of last month, and brings a Twitter-like – or, rather, Weibo-like feel to the BBS genre, with users able to ‘follow’ forums and post discussions. One troublesome aspect might be Sina’s need to police its new feature very carefully, applying the same media directives – ie: censorship – to Weiba that it does to Weibo as a whole. (Baidu had to cripple its own Tieba forums recently, at the behest of authorities). One example is the way that Weibo was seemingly cleansed of photos of the recent Hong Kong protests. Going forward, we expect Weiba to be controlled just as tightly.

For the now massive Sina Weibo platform, it’s one more feature alongside many others, such as Tumblr-esque light blogs and social gaming.