Sina Weibo the domestic microblogging services including the first weibo service Fanfou. Many popular non-China-based microblogging services like Twitter, Facebook, and Plurk have been blocked from viewing since then. Sina's CEO Charles Chao considered this to be an opportunity. SINA Corporation launched the tested version of Sina Weibo on 14 August 2009. Basic functions including message, private message, comment and re-post were made possible in September 2009. A Sina Weibo–compatible API platform for developing third-party applications was launched on 28 July 2010. On 1 December 2010, the website experienced an outage, which administrators later said was due to the increasing numbers of
Sina Weibo Class requirements. The Sina Weibo financial report in February 2013 showed that its total revenue was approximately US$66 million and the number of registered users exceeded the 500 million mark. In April 2013, Sina officially announced that Sina Weibo had signed a strategic cooperation agreement with Alibaba. The two sides conducted in-depth cooperation in areas such as user account interoperability, data exchange, online payment, and internet marketing. At the same time, Sina announced that Alibaba, through its wholly owned subsidiary, purchased the preferred shares and common shares issued by Sina Weibo Company for US$586 million, which accounted for approximately 18%