OpenAI Taps Magnite and PubMatic to Sell Unused ChatGPT Ad Space, Widening Its Ad Tech Push

OpenAI has signed agreements with ad technology companies Magnite (MGNI) and PubMatic (PUBM) to sell ChatGPT advertising space that would otherwise go unsold, according to a published report citing three people familiar with the deals. Advertisers can set budgets, submit bids and upload ads through the two companies' platforms, while OpenAI keeps control over where ads are placed and delivered.

What the deals do

Magnite and PubMatic are best known as supply-side platforms, the software publishers use to sell ad space to buyers. Under the reported arrangement, their tools become another route for advertisers to buy ChatGPT inventory using the budgeting, bidding and creative-upload workflows they already use elsewhere. Ad volume through both platforms is still small, according to the report, but the companies expect it to grow quickly as more advertisers gain access through familiar buying tools. Financial terms have not been disclosed.

OpenAI's growing ad tech network

The agreements add to a list of ad technology and measurement partners that OpenAI has assembled since it began testing ads in ChatGPT in February.

Lower prices, new formats

OpenAI has also been lowering the cost of entry. The pilot launched with a CPM, the price per thousand impressions, of about $60 and minimum commitments of $200,000 to $250,000. Reported CPMs fell to as low as $25 by April, the minimum spend dropped to $50,000 with the launch of a self-serve ads manager, and later opened with no minimum. OpenAI added cost-per-click bidding as well. The report says it has introduced interactive ads that let users chat directly with brands; OpenAI has described current ads as sponsored links beneath answers and has said it is testing other formats, so the scope of the interactive format is not yet clear.

Cheaper inventory and more buying channels have a clear logic. By our calculation, a CPM cut from $60 to $25 is a 58% reduction, and lower prices tend to pull in smaller advertisers, who often buy through platforms like these rather than directly. The pilot passed $100 million in annualized revenue in under two months with fewer than 600 advertisers, according to published reports, and OpenAI has said its ads business is on track to exceed $1 billion over the next 12 months.

Why it matters for Magnite and PubMatic

For both companies, ChatGPT is a new source of demand and inventory at a time when the open web, connected TV and retail media dominate their business. A relationship with OpenAI would be a signal that AI assistants can be sold through programmatic tools, but the report describes early, small volume, so any revenue contribution is likely to take time. Investors will look for management commentary on the size and timing of that revenue.

What to watch

• Magnite earnings. The company reports third-quarter results on Wednesday, Nov. 4, after the market close, with a call at 4:30 p.m. ET. Details are on its investor relations site.
• Disclosure. Whether either company puts numbers on ChatGPT volume, or says if the relationship is exclusive or limited to unsold inventory.
• Ad rates. Further cuts would widen access but could pressure revenue per impression for partners.
• Formats and measurement. Interactive ads and third-party measurement will shape how much budget big brands commit.
• Wider AI trade. See our coverage of the Anthropic S-1 amendment and the Research Desk analysis of the tech selloff.

Sources: Magnite's investor relations page for the Nov. 4 results date. The deal details, partner list and pricing history come from published reports and company announcements, and ad prices are reported estimates that change. Items labeled by our calculation are our own arithmetic. This article is informational only and is not investment advice.