Weibo has 129 million active monthly users

"According to the IPO documents, Weibo pulled in revenues of $188.3 million in 2013. Like its U.S. counterpart Twitter, however, the company is still not turning a profit at the bottom line: Weibo recorded a $38.1 million net loss in 2013. The company had 2,043 employees as of December 2013.
“Since our inception four years ago, Weibo has amassed a large user base in China and in Chinese communities in more than 190 countries. In December 2013, Weibo had 129.1 million monthly active users, or MAUs, and 61.4 million average daily active users, or average DAUs, increasing from 96.7 million MAUs and 45.1 million average DAUs in December 2012, respectively, and 72.9 million MAUs and 25.2 million average DAUs in December 2011, respectively. A microcosm of Chinese society, Weibo has attracted a wide range of users, including ordinary people, celebrities and other public figures, as well as organizations such as media outlets, businesses, government agencies and charities.”"

Source:  Weibo's IPO document, reported by TechCrunch, 14th March 2014