Sina Weibo has said that it now has about 450,000 users in the United States out of its total of 250 million as of late November. There is no official record of the nationality of the US users. They could be US citizens, Chinese students or people from other countries, state run China Daily reported.
Its users included philanthropist Bill Gates of Microsoft, International Monetary Fund Chief Christine Lagarde and actor Tom Cruise, who started using it to step up interaction with Chinese public, the report said.
Lagarde made her Weibo debut in early November, posting her first message which reads: "Hello Sina Weibo, looking forward to sharing updates here."
By the end of the day, Lagarde's account had drawn about 40,000 followers and had more than 1,000 comments. She currently commands 150,000 followers.
Gates is a popular Sina Weibo user, currently with 2.19
Recognising Weibo's importance, almost all foreign missions, including the Indian Embassy, have started their Weibo tweets to highlight their activities and policies of their countries.
The site also helped politicians like San Francisco Mayor Ed Lee, a Chinese-American, to reach Chinese audiences during the recent mayoral elections.
During the election day in November, Lee posted messages calling for support. Later that day the first elected Chinese-American mayor posted to his followers on the site: "Thank you San Francisco!"
Kenneth Wisnefski, founder and CEO of WebiMax, a US-based search engine optimisation firm, said Sina Weibo is following the same development pattern as Twitter, which took about two years to be fully accepted before it became the dominant social media platform it is today.
Weibo's overseas users mostly utilise the service to reach Chinese audiences.
And for celebrities, their reason is quite simple: to promote themselves or their programme in China.
China's total Internet users hit 450 million early this year - larger than the whole US population - and that number is expected to grow.