Elon Musk's X has signed up a new adtech partner as it looks to bring on more advertisers

• Elon Musk's X is working with the adtech company Magnite to boost programmatic ad sales.
• Magnite is a large supply-side platform, which helps publishers monetize their sites and apps.
• X has recently been expanding its ad partnerships.

Elon Musk's X has signed a partnership with the adtech company Magnite, the latest in a string of deals it has signed with programmatic advertising firms, Business Insider has learned.

Magnite operates a supply-side platform, technology that helps web publishers, app developers, and streaming TV providers manage and sell advertising. It's one of the largest SSPs in the US by market share, according to the analytics platform Pixalate.

A spokesperson for Magnite confirmed the partnership with X and said it offers advertisers an option to include or exclude X's inventory from their media buys.

X didn't immediately respond to a request for comment.

Magnite joins Google and PubMatic as official third-party sellers of X's ad inventory. X had also previously forged a partnership with InMobi, but the adtech company hasn't offered ads on X for well over a year, as BI previously reported.

By opening up its ad inventory to partners, X can theoretically tap into additional advertiser demand — including companies that may not have previously considered buying X or other social-media ads.

It could help fill gaps that X's sales team and self-service buying platform couldn't sell. That said, it's likely these would be bought at a lower price, and X would have to share some of that revenue with its adtech partners.

Prior to Musk's takeover of the company (previously called Twitter), it only sold directly and didn't make its inventory available to third-party adtech vendors.

X has been working to reverse the large revenue shortfall that came as many advertisers pulled or dramatically reduced their spending on the platform after Musk's takeover of the company in 2022. X laid off swaths of its safety and sales staff, loosened content moderation rules, switched up its verification system, and allowed previously banned accounts back onto the platform.

Musk's own behavior toward advertisers has sometimes not been cordial. He famously told companies that had pulled advertising from X to "go fuck yourself" during a 2023 onstage interview. X is also currently suing 11 advertisers, alleging they collectively conspired to boycott X through their membership in a now-defunct trade body initiative called the Global Alliance for Responsible Media.

MediaRadar, a marketing intelligence firm, estimated that X's US advertising revenue came in at $1.4 billion in 2024, down 28% from the nearly $2 billion spent on the platform in 2023. The number of companies advertising on X in 2024 increased 15% year-over-year, per MediaRadar, which analyzes a panel of more than 2 million US users.

Despite some struggles on the advertising side, X remains an influential platform under Musk, who has been in the spotlight as a powerful political figure following President Donald Trump's reelection.