OpenAI's measurement gap is capping ChatGPT ad budgets
Seven months after ads went live inside ChatGPT, agencies say conversions go missing, arrive late or fail to match their own tracking, and brands are keeping spend at test level. For marketing leaders, this is a live decision about how much money moves into a channel that still grades its own homework.
Ada BrandtBrand & Marketing StrategistOctober 2, 2026Listen to the podcast
8 min
Chapters
Key takeaways
- Define your KPIs and an independent measurement framework in writing before any ChatGPT ad spend, rather than accepting platform reporting at face value.
- Run a geographic holdout, switching the channel off in matched regions, so results do not depend on OpenAI's own conversion counting.
- Put OpenAI's conversion tracking terms in front of your legal team now with a decision date, since you cannot argue about data you refuse to collect.
- Keep ChatGPT ads funded from test money until OpenAI names third-party measurement partners with a timeline, not just an intention.
- Track whether conversion-optimised bidding produces a stable cost per acquisition in your own category before shifting budget from Google or Meta.
Read the full transcript
Host:Welcome back to Leaders Insights. OpenAI's measurement gap is capping ChatGPT ad budgets, and why it matters this week. An agency runs a lead generation campaign inside ChatGPT, the forms are filling up on their side, and the platform reports zero conversions. Two weeks later, still zero. Is that a bug or is that the product?
Expert:That is the Accuracast case Digiday published on October 1, and I would call it a product that is younger than its ambitions. The agency ran a UK lead generation campaign on ChatGPT alone, watched the form fills come in, and two weeks later the platform still showed zero conversions. Lead generation here means a campaign whose success is someone filling in a form, so the conversions are the entire point. The same agency found ChatGPT reporting around 100 clicks where its own tracking picked up 20, and OpenAI's support team at the time could not say why.
Host:A hundred against twenty. That is a five to one gap on the most basic number in digital media.
Expert:It is, and the direction matters. Accuracast's group CEO Farhad Divecha told Digiday the problem on Google and Meta tends to be the opposite, with the platforms claiming more conversions than they drove. So the usual industry suspicion, that a platform flatters itself, is not quite the story here. One agency saw more clicks reported than it could find, and conversions it could see going unreported. That is noise in both directions, which is harder to plan around than a known bias.
Host:Before we build a thesis on one agency, who disagrees?
Expert:Plenty. Digiday says execs from AdRoll, Jellyfish and another independent US agency had not seen click discrepancies. A different firm, Web Guide Partner, framed it as a timing problem: conversions that do register arrive 24 to 36 hours late against a few hours on Google, and the reporting carries no demographic or prompt data. My opinion, not reported fact: late and thin is a workable problem, missing is not. If you cannot see the outcome at all, you cannot defend the line item.
Host:Let me put the uncomfortable version to you. Marketers are complaining about a platform they themselves refuse to feed. Is this not partly self-inflicted?
Expert:Largely, yes. Those tracking problems only apply to advertisers who have switched conversion tracking on, and many have not, because doing so means signing OpenAI's tracking terms, which legal teams at a lot of advertisers will not sign, citing liability. Digiday describes it as a catch-22: advertisers need to give OpenAI better data for its conversion tracking to improve, but the advertisers with the most data are the least willing to hand it over, and without reliable conversion data OpenAI cannot offer the optimisation that makes Google and Meta useful to performance marketers.
Host:So what are people actually buying on, in the meantime?
Expert:Shallow signals. Many advertisers are still optimising toward clicks or impressions, though that is starting to change as conversion-optimised bidding becomes more common, giving some ability to bid toward cost per acquisition, the price you are willing to pay for one customer action. Jellyfish's Victor Batista told Digiday the bigger shift comes when OpenAI builds optimisation toward metrics like cost per acquisition or return on ad spend, which is revenue divided by media cost, and that requires OpenAI to have confidence in its own numbers first. Until then, advertisers are bidding with little to go on.
Host:Delivery itself sounds unstable too.
Expert:Divecha's words to Digiday were that the biggest issue is inventory, that it is not predictable, that there is room to serve more, and that there is no obvious explanation for the change. Inventory here means the number of chat responses available to carry an ad. If that supply moves without warning, your spend pacing moves with it, and a weekly report stops being a report and becomes a guess.
Host:Why is anybody still in, then?
Expert:Two reasons, one commercial and one political. The commercial one: this is now a real buying channel. Cost per click has been introduced since launch and now accounts for most of the ad spend, according to Digiday. In Europe, advertisers in the new markets can buy through Publicis, Omnicom, WPP, Havas, Dentsu and MediaPlus. The political reason is that no CMO wants to explain to a board why a competitor was in the room first. Batista put the honest version on the record: the platform is still very much unproven, very new, built at a fast pace, and the platform in use now is not the one released in the pilot, it has grown massively.
Host:Independent verification. Where is it, and does it fix any of this?
Expert:It is arriving slowly and it fixes less than people hope. OpenAI's ads and monetisation lead Asad Awan told a press briefing that third-party measurement was in the works, without partners or an exact timeline. Since then LiveRamp, the data matching firm, became the first independent ad tech company to pipe conversion data into OpenAI's conversions API, which is a server to server feed that sends purchase events back to the platform, and that deal is tightly scoped: US only for now, limited to select mutual clients. OpenAI has also signed mobile measurement partners including AppsFlyer and Adjust, which matters because so much ChatGPT use happens in the app. And the caveat that should go on a slide: Divecha said a verification partner would confirm ads were seen without showing whether they worked.
Host:Give me the strongest argument against your own caution.
Expert:It is a good one. Every large ad platform looked like this in year one, with thin reporting, odd delivery and no outside auditor, and the advertisers who learned the auction early paid less for years afterwards. Digiday also notes OpenAI is carrying infrastructure costs that far outweigh revenue, and ads are now core to lightening that load, which is a strong incentive to fix measurement fast rather than slowly. If you wait for a mature measurement stack, you will arrive when prices reflect certainty. The counter to the counter is that a two week blind spot on conversions is not a rounding error, it is the difference between a test and a budget transfer.
Host:You have one minute. What should a marketing leader do this week?
Expert:One thing, and it is not a bigger budget. Decide your measurement before you spend, in writing. Mile Marker's vp of biddable centre of excellence Monica Shukla told Digiday it was important to establish an independent measurement framework before testing the platform rather than taking its own reporting at face value, and her point was to define the KPIs first and go back to them, instead of accepting platform-first metrics and data at face value. In practice that means a geographic holdout, where you switch the channel off in matched regions and compare, so the answer does not depend on OpenAI's own counting. Then do the boring task: put the tracking terms in front of your legal team now, with a decision date, because you are currently arguing about numbers you have refused to collect.
Host:And what to watch.
Expert:Two markers. Whether OpenAI names third-party measurement partners with a timeline rather than an intention, and whether conversion-optimised bidding starts delivering a stable cost per acquisition in your own category. Until both move, keep this funded from test money and keep your reconciliation sheet open next to the dashboard.
Host:Sources for today's episode: OpenAI's measurement gaps are keeping ChatGPT ads budgets at test level, Delivery Apps And Retailers Unite; How Do You Measure, Measure An Ad, OpenAI takes ChatGPT ads into Europe, OpenAI opens up ChatGPT ads manager to the U.S. while promising third-party measurement, CPA bidding, OpenAI’s ads get their first measurement partner in LiveRamp. That's it. The CMO decision tools are live at mba-training.com.
According to Digiday, seven months after OpenAI started selling ads in ChatGPT, marketers are still asking how they are supposed to measure them, and it has become the sticking point in almost every conversation the publication has had about the company as an ad seller, driven partly by a sense that OpenAI has not built much beyond the basics and partly by marketers' reluctance to hand over their data.
The specifics are uncomfortable. Digiday reports that the agency Accuracast ran a UK lead generationlead generationMarketing activities designed to attract and capture contact information from prospects interested in your offer, creating a pipeline of potential customers.View full definition → campaign on ChatGPT alone and watched form fills arrive while the platform still showed zero conversions two weeks later, and that the same agency saw around 100 clicks reported where its own tracking picked up 20, with OpenAI's support team unable to explain why. AdExchanger picked up the click discrepancy the next day, noting OpenAI could not explain it. Where conversions do register, Web Guide Partner told Digiday they land 24 to 36 hours late against a few hours on Google, and reporting carries no demographic or prompt data.
What is contested: the experience is not universal. Digiday says execs at AdRoll, Jellyfish and another independent US agency had not seen click discrepancies. The problems also only apply to advertisers who have switched conversion tracking on, and many have not, because doing so means signing OpenAI's tracking terms that plenty of legal teams refuse on liability grounds. That leaves a loop: advertisers want Google-grade optimisation, but OpenAI cannot deliver it without the conversion data those same advertisers will not share.
Why it matters for budget owners: cost per clickcost per clickCost Per Click (CPC) is the average amount you pay each time someone clicks your ad. It is a core pricing metric for paid search and social advertising.View full definition → now accounts for most ChatGPT ad spend, according to Digiday, and Jellyfish's Victor Batista said the bigger shift comes when OpenAI optimises toward cost per acquisitioncost per acquisitionCost Per Acquisition: the total cost to generate one customer or conversion, computed by dividing total spend by the number of acquisitions.View full definition → or return on ad spendreturn on ad spendReturn on Ad Spend (ROAS) measures the revenue generated for every unit of currency spent on advertising, calculated as revenue divided by ad cost.View full definition →, which requires OpenAI to trust its own numbers first; until then advertisers bid with little to go on.
What to watch: independent measurement. OpenAI's ads and monetisation lead Asad Awan told a press briefing that third-party measurement was in the works without partners or a timeline. LiveRamp has since become the first independent ad tech company piping conversion data into OpenAI's conversions APIAPIApplication Programming Interface: a standardised interface that lets applications communicate and exchange data without knowing each other's internal workings.View full definition →, scoped to the US and select mutual clients. AppsFlyer and Adjust are signed as mobile measurement partners.
Sources
- OpenAI's measurement gaps are keeping ChatGPT ads budgets at test level
- Delivery Apps And Retailers Unite; How Do You Measure, Measure An Ad
- OpenAI takes ChatGPT ads into Europe
- OpenAI opens up ChatGPT ads manager to the U.S. while promising third-party measurement, CPA bidding
- OpenAI’s ads get their first measurement partner in LiveRamp
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