Twitter’s valuation has since plunged. In March, Mr. Musk said the company was worth $20 billion, down more than 50 percent from the $44 billion he paid for it. Last week, the mutual funds giant Fidelity, which owns shares in Twitter, valued the company at $15 billion.
Twitter feels increasingly “unpredictable and chaotic,” said Jason Kint, chief executive of Digital Content Next, an association for premium publishers. “Advertisers want to run in an environment where they are comfortable and can send a signal about their brand,” he added.
Some of Twitter’s biggest advertisers — including Apple, Amazon and Disney — have been spending less on the platform than last year, three former and current Twitter employees said. Large specialized “banner” ads on Twitter’s trends page, which can cost $500,000 for 24 hours and are almost always bought by large brands to promote events, shows or movies, are often going unfilled, they said.
Twitter has also run into public relations snafus with big advertisers like Disney. In April, Twitter mistakenly gave a gold check mark — a badge meant to signify a paying advertiser — to the @DisneyJuniorUK account, which Disney doesn’t own. The account posted racial slurs, leading Disney officials to demand from Twitter an explanation and assurances that it wouldn’t happen again, two people with knowledge of the situation said.
Disney, Apple and Amazon declined to comment.
Six ad agency executives who have worked with Twitter said their clients continued to limit spending on the platform. They cited confusion over Mr. Musk’s changes to the service, inconsistent support from Twitter and concerns about the persistent presence of misleading and toxic content on the platform.
Last month, for instance, a picture that appeared to show an explosion near the Pentagon — which artificial intelligence experts identified as a synthetically generated image — was shared by dozens of Twitter accounts and briefly caused the stock market to tumble.
Some advertisers also continue to worry about Mr. Musk’s tweets. Last month, he posted several times comparing the billionaire financier George Soros, a frequent target for conspiracy theorists, to the “X-Men” comic book villain Magneto. Ted Deutch, the chief executive of the American Jewish Committee, noted that both Mr. Soros and Magneto are Holocaust survivors, and that “the lie Jews want to destroy civilization has led to the persecution of Jewish people for centuries.”