As reported in Insider:

“This is a drop we have not seen before for any major advertising platform,” said Ruben Schreurs, Ebiquity’s chief strategy officer.

“The recent claims by X’s leadership around the mass return of top advertisers buying ads on their platform has puzzled us,” said Ebiquity’s Schreurs, who added that the consultancy’s work with clients and discussions with advertiser trade body groups hadn’t provided any indicators that big advertisers were back on X.

Ebiquity’s analysis has led to “serious concerns about the trustworthiness of public statements made by Musk and Yaccarino,” Schreurs said.

A number of advertisers have stopped or drastically reduced their spending on X over the past year, amid concerns about the content it hosts and the general reliability and effectiveness of its ad platform.

A separate analysis, from the advertising analytics firm Guideline, found that X’s US ad revenue has dropped 55% or more each month since Musk’s takeover. A review of data from Sensor Tower conducted by progressive watchdog group Media Matters found that while some advertisers had technically returned to purchasing ads on X, they were doing so at just a fraction of the level of their previous spend. Visa, for example, spent $10 in the 12 weeks to October 6, compared to $77,500 during the same period last year, according to Sensor Tower’s data.