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The new regulations, which require users to pass personal information to Sina, could empower the firm to target users with advertising and to collect useful data on them, analysts said.

Sina on Monday estimated that 60 percent of its 300 million users of Weibo users would have registered their real identities by the deadline.

Harrington said he estimates that new rules could see a pent up demand for big brands to advertise on Weibo.

"If I could tell all my customers tomorrow that they could buy their brand keywords on Weibo, they will buy them immediately," he said.

Chief Executive Charles Chao said in an earnings call last month he expects to start monetising Weibo effectively in the second half of the year through advertising.

The real-identity rules would also make it harder for spam accounts to operate. Chao told local media late last year that Sina recently removed tens of millions of spam accounts.

When the real-identity rules were announced by the Beijing city government on Dec. 16, Sina shares plunged to its lowest in 15 months on concern that the rules would neuter discussion and engagement on the lively platform.

The company said during the earnings call that the rules would have a negative impact on user engagement but analysts said the rules would not affect the platform's popularity in the medium to long term.

"I would expect it to trend down just a little bit but probably not dramatically," said Michael Clendenin of RedTech Advisors.

China has repeatedly criticised microblogs for spreading what it calls unfounded rumours and blocks social networking sites such as Twitter and Facebook, citing the need to maintain social stability.

"The vast majority of users are not publishing sensitive information, they are using it as a documentation of their daily lives," said Sam Flemming, founder of Shanghai-based social media consultancy CIC.

"I don't see that this would really impact their use of the platform," Flemming said.