More than 10 million people have signed up for X in December, X CEO Linda Yaccarino said in a post on the social media platform on Thursday.

This comes as the company, formerly known as Twitter, risks losing as much $75 million in advertising revenue by the end of the year as major brands pause their marketing campaigns on the platform, according to the New York Times.

X, which does not regularly release user data, could not immediately be reached for comment on how the December sign-ups compared to average or why Yaccarino disclosed the figure. Billionaire owner Elon Musk said in July the site had 540 million monthly users.

Several companies, including Apple, Disney, Warner Bros Discovery , Comcast, Lions Gate Entertainment , Paramount Global, and IBM said in November they were pausing their advertisements on X.

Musk cursed advertisers that fled the platform after he agreed with a user who falsely claimed Jewish people were stoking hatred against white people.

A report from watchdog group Media Matters found ads from major companies next to X posts that supported Nazism. The platform filed a lawsuit in late November against Media Matters accusing it of defamation.