Sina Weibo claimed over 250 million users in its conference call for financial results dated September 30, 2011.

However, the Chinese portal site losses US$ 336.3 million in Q3 largely due to lousy investments even though Q3 revenue reached US$ 130.3 million, increased 20% year over year.

Charles Chao, Sina CEO talked about Weibo saying:”Half of our weibo users have upgraded to the new Version 4.0 since its launch in this September and we witnessed a fast user growth. Now we’ve shifted and sharpened our focus on adding more social features to weibo to enhance user traction.” He also mentioned that Sina’s advertising revenue recorded $ 100 million for the third quarter.