Companies that wish to advertise on Twitter Inc. are now required to pay for verification or reach a minimum monthly spend on ads, the social media platform told advertisers this week.

As of Friday, advertising will only be available to verified accounts, including individuals who pay $8 per month for Twitter Blue and “Verified Organizations” that pay $1,000 for a gold or gray check mark, the company wrote in an email seen by Bloomberg.

Businesses that already spend $1,000 a month on ads will be allowed to continue and will be given a gold check mark, the company added.

The change to Twitter’s advertising rules is part of a wider strategy to remove fake accounts and bots and “elevate the quality of content on Twitter and enhance your experience as a user and advertiser,” the company said in the email.

Twitter has been experimenting with different monetization strategies since it was acquired by Elon Musk last year, including charging for verification and API access. Its paid-for verification model initially failed to gain traction as many prominent accounts had been verified for free in the past. However, this week the company stripped these “legacy verified” accounts of their blue checks and restricted some product features, including the ability to edit tweets, to subscribers of Twitter Blue.

The new advertising policy has caused some digital marketing businesses to change strategy.

“We are already moving budget away on projects launching next week, with the uncertainty on whether clients want verification, or how long it will take to go process,” said Tom Davenport, managing director of UK-based media agency Digital Marketing Specialist Ltd. Revenues from advertising had wained after Musk’s takeover, with the SpaceX and Tesla boss’s online activity causing concerns for the brand safety of the platform. Several large media agencies advised clients to suspend campaigns.

Social media consultant Matt Navarra said the change could be the “last straw” for advertisers already losing their patience with Musk.

“If he had any hope of inspiring brands and advertisers to return to the platform or to spend more, things like this are going to completely go against him,” he said.

After Twitter removed legacy blue checks on accounts on Thursday, Musk disclosed that he was “personally paying” for the Twitter Blue subscriptions of three accounts: those of basketball player Lebron James, author Stephen King, and actor William Shatner.

Twitter did not meaningfully respond to a request for comment.

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