Sina Weibo China's microblogging market based on active users and 86.6% based on browsing time over competitors such as Tencent Weibo and Baidu's services. The top 100 users had over 485 million followers combined. Furthermore, Sina said that more than 5,000 companies and 2,700 media organizations in China use Sina Weibo. The site is maintained by a growing microblogging department of 200 employees responsible for technology, design, operations, and marketing. Sina executives invited and persuaded many Chinese celebrities to join the platform. The users of Sina Weibo include Asian celebrities, movie stars, singers, famous business and media figures, athletes, scholars, artists, organizations,
Sina Weibo Attempts to register accounts with usernames alluding to Ai Weiwei were blocked. On 30 March 2010, Hong Kong singer Gigi Leung blogged about the jailed Zhao Lianhai, an activist and father to a 2008 Chinese milk scandal victim. The post was later deleted by an administrator. However compared to other Chinese media formats, Weibo services are seen as allowing greater freedom of speech. Criticism against the Chinese government is more widespread on Sina Weibo and other weibo services. After the July 2011 Wenzhou train collision, many dissatisfied posts concerning governmental corruption were posted throughout the Sina Weibo. While Weibo services