According to the news, Sina Weibo started internal test of its membership system.
According to this picture, if user join this membership, they can get a lot of various privilege on Sina Weibo. And this membership might be provided as a professional service, it's estimated Sina will use the system of their own virtual money "Weibi".
Of course Sina Weibo have to increase their users as before, but in addition they have to aim for its monetization in future. So it may be Sina Weibo will start this system as one of professional service.
Original article => China microblogging Trivia