ChatGPT's advertising business has crossed a $1 billion annualized revenue run rate, and the composition of who buys those ads has shifted sharply toward financial services companies over a four-month stretch, according to Sensor Tower.

The market intelligence firm published the findings on September 1, 2026, in a report titled "ChatGPT's Ads Business Gains on Rising Density and a Broadening Advertiser Mix." The report documents three parallel trends inside OpenAI's advertising network: rising ad density per user, a fast-growing pool of unique advertisers, and a pronounced rotation away from shopping and retail spend toward financial services, software, travel and health and wellness categories.

According to Sensor Tower, the number of ads shown per user per hour of time spent on ChatGPT's mobile app in the United States rose 163% in August 2026 compared with April 2026. Broken into monthly increments, ad density climbed at an average rate of 26% month-over-month across that same four-month window. The firm's analysts wrote that the trend "likely suggests greater ad supply and willingness to ramp ads throughout the user experience."

A new format enters the mix

OpenAI introduced carousel ads in August 2026, giving advertisers a way to display multiple products within a single placement rather than the single sponsored unit that had defined ChatGPT advertising since the pilot's February 9, 2026 launch. Sensor Tower estimated that roughly 23% of all ChatGPT ads placed on desktop in the United States between August 15 and August 30, 2026, were carousel ads - a rapid adoption curve for a format that had only existed in test form weeks earlier.

PPC Land reported on the carousel format's arrival in early August, when OpenAI confirmed it was testing a multi-product carousel unit for product feed campaigns alongside a separate change requiring advertisers to opt out of automatic advanced matching by August 17, 2026. At the time, commerce specialist Brodie Clark described the format as live on X, calling it "big news for advertising in ChatGPT for eCommerce stores." The format's structural significance, as PPC Land noted then, is that it breaks the one-advertiser, one-product constraint that had governed ChatGPT ad units from the start.

Advertiser count keeps climbing

Sensor Tower counted approximately 1,200 unique advertisers spending on ChatGPT in the United States during August 2026, across both mobile and desktop placements. That population has grown at an average of 43% month-over-month between May and August 2026. The growth rate is notable because it has held steady even as OpenAI simultaneously expanded the platform into new international markets and added new product features, any one of which might have been expected to slow adoption while advertisers adjusted.

Other measurement firms have tracked similar growth from different angles. Adthena, a London-founded search intelligence company, counted 7,378 distinct ChatGPT advertisers during the week of July 13 to 20, 2026, with the United States accounting for 60.1% of that total. The two figures are not directly comparable - Adthena's count spans a single week of global advertiser activity while Sensor Tower's is a monthly US-only figure drawn from its own panel - but both point in the same direction: a rapidly expanding buyer base rather than a plateau.

Shopping's share falls as new categories rise

The most striking shift in the Sensor Tower report concerns advertiser mix. Shopping and retail advertisers accounted for 37% of total US ad spend on ChatGPT in April 2026. By August 2026, that share had fallen to 21%, even though shopping and retail advertisers still represented the largest single category.

The categories that filled the gap were spread across several verticals rather than concentrated in one. Software rose from 13% to 16% of total US ad spend over the same period. Financial services climbed from 2% to 13%. Travel increased from 5% to 11%. Health and wellness grew from 1% to 5%. Taken together, those four categories moved from a combined 21% of spend in April to 45% by August, roughly doubling their collective share of the network's revenue in four months.

Financial services stood out for the speed and concentration of its growth. Sensor Tower found that four of the ten highest-spending advertisers on ChatGPT in the United States during August 2026 were financial services companies. In April 2026, by contrast, Intuit was the only financial services company to appear anywhere in the platform's top 100 spending advertisers list. The firm's analysts described the shift as "a radical shift compared to just a few months ago."

Why financial services moved differently

The scale of the financial services jump separates it from the broader vertical diversification story. A category moving from thirteenth-place obscurity - a single advertiser in the top 100 - to supplying nearly half of the top ten spenders within four months indicates something closer to a coordinated category entry than gradual organic uptake. Financial products such as loans, credit cards, insurance and tax preparation software carry comparatively high customer lifetime value, which may make marketers in that sector willing to test emerging channels earlier and more aggressively than lower-margin retail categories once a platform demonstrates baseline traffic and measurement infrastructure.

That infrastructure has been building for months. OpenAI's self-serve Ads Manager opened to all US businesses on May 5, 2026, introducing cost-per-click bidding alongside the existing cost-per-mille model and confirming a Conversions API and pixel-based measurement tools. LiveRamp connected its Conversions API Hub to ChatGPT the following month, giving marketers a server-to-server measurement option less exposed to browser tracking limitations than client-side pixels. Financial services marketers, who typically operate under stricter compliance and attribution requirements than retail categories, may have needed that measurement layer in place before committing meaningful budget.

The billion-dollar run rate

Sensor Tower's report frames its findings against what it calls a "historic milestone": ChatGPT's advertising business reaching a $1 billion annualized revenue run rate. The firm did not publish the underlying monthly revenue figure in the version of the report reviewed by PPC Land.

The milestone itself was first reported publicly two days before Sensor Tower's analysis. PPC Land reported that Digiday disclosed on August 31, 2026, that OpenAI's advertising business had reached the $1 billion annualized run rate in under 200 days, a figure derived by multiplying current monthly revenue of roughly $83 million by twelve. An annualized run rate is a projection based on a single month's performance rather than revenue actually collected over a full year, meaning the figure describes momentum rather than booked income. Self-serve advertiser access opened the same day across the 31 European markets where ChatGPT ads had launched earlier in August 2026.

The run rate's trajectory has moved quickly since the pilot began. OpenAI's advertising pilot crossed $100 million in annualized revenue within six weeks of its February 9, 2026 launch, according to a company spokesperson quoted by Reuters at the time. Reaching ten times that figure by early September 2026 places the advertising business on a growth curve that, if sustained, would carry significant weight against OpenAI's own longer-term ambitions. As PPC Land noted in its coverage of the billion-dollar threshold, sustaining a path toward the $100 billion revenue target OpenAI has set for 2030 would require compound annual growth of 216.2%, according to Digiday's Seb Joseph and Krystal Scanlon.

Geographic and product expansion ran alongside the mix shift

The advertiser mix shift did not happen in isolation. Over the same April-to-August window, OpenAI activated ChatGPT ads in a sequence of new markets. The company expanded advertising into Japan and South Korea and opened self-serve access to United Kingdom advertisers in July 2026. Brazil and Mexico followed, and OpenAI added Latin American markets in mid-August 2026, bringing the advertising footprint to nine countries at that point. Days later, the platform's largest single expansion arrived: ChatGPT ads reached 31 European markets before the end of August 2026, running on the Free and Go subscription tiers.

Product changes accompanied the geographic rollout. Automatic advanced matching, a technique that uses hashed customer data collected from website forms to attribute more conversions to ads, became the default setting for new web pixels and, from August 17, 2026, for existing ones as well. Conversion-optimized bidding extended to product feed campaigns. A new automated bid strategy called Maximize results, which OpenAI made the preselected default for eligible new ad groups, arrived in the same week Mexico and Brazil went live and the week before European inventory opened.

None of these changes explains the financial services concentration on its own, but together they describe a platform that added distribution, measurement and automation capacity in rapid succession - the kind of infrastructure buildout that tends to precede, rather than follow, adoption by advertisers in more heavily regulated categories.

What the numbers do not show

Sensor Tower's estimates are drawn from what the firm describes as its proprietary panel and data science models, and the company states plainly in its own disclaimer that the figures "may not accurately represent metrics for any app or advertiser," positioning them as directional trend indicators rather than exact measurement. The report does not disclose absolute dollar figures for any of the vertical categories, only their share of total US ad spend, so a category's percentage growth does not by itself indicate whether total ChatGPT ad spend in dollar terms from that sector actually increased, held steady, or even declined in absolute terms if overall network spend grew fast enough elsewhere.

The report also does not specify which financial services companies ranked among the top ten spenders in August 2026, nor does it break down whether that spend came from lenders, insurers, payment processors, or another financial subsector. Independent measurement of ChatGPT's advertiser base varies depending on methodology: Adthena's weekly advertiser count, Similarweb's ad-frequency figures and Sensor Tower's monthly US panel each use different collection windows and geographic scopes, a pattern that has made cross-referencing figures from different measurement firms an ongoing challenge for anyone tracking the channel's growth.

Why this matters for marketers

The Sensor Tower findings arrive at a point where ChatGPT advertising has moved from an experimental pilot to a channel with measurable scale and an increasingly professionalized buyer base. For performance marketers and media planners, the vertical mix shift is a signal worth watching closely: a channel that shopping and retail advertisers largely built in its first months is now attracting categories - financial services chief among them - that typically demand stronger compliance tooling, more rigorous attribution, and higher creative scrutiny before committing budget.

That financial services firms moved from a single top-100 advertiser to four of the top ten in four months suggests the category assessed the platform's measurement infrastructure, found it adequate, and moved with unusual speed once it did. Marketers in adjacent regulated categories - insurance, healthcare, legal services - watching this data may draw the conclusion that the infrastructure gap that previously kept them out of conversational AI advertising is closing faster than the broader narrative around the channel suggests.

The rise in ad density carries its own implications. A 163% increase in ads shown per user per hour points toward a platform actively testing how much advertising its user base will tolerate, a question every ad-supported product eventually confronts. Whether that density increase pressures auction prices upward, as some analysts have already predicted in connection with the carousel format's introduction, will likely become clearer as OpenAI publishes further data or as third-party measurement firms continue tracking the network through the remainder of 2026.

Timeline

  • February 9, 2026 - OpenAI formally starts the ChatGPT advertising pilot in the United States.
  • March 26, 2026 - OpenAI's advertising pilot crosses $100 million in annualized revenue within six weeks of launch, with over 600 advertisers enrolled.
  • May 5, 2026 - OpenAI opens a self-serve Ads Manager to all US businesses, adding CPC bidding and a Conversions API.
  • June 2026 - LiveRamp connects its Conversions API Hub to ChatGPT for server-to-server conversion measurement.
  • July 2026 - ChatGPT ads expand to Japan and South Korea, and self-serve access opens to United Kingdom advertisers.
  • Early August 2026 - OpenAI tests a multi-product carousel format for product feed ads and sets an August 17, 2026 default date for automatic advanced matching.
  • Mid-August 2026 - ChatGPT ads activate in Mexico and Brazil, bringing the market count to nine, alongside a new default automated bid strategy.
  • August 2026 - OpenAI makes carousel ads a standard format; Sensor Tower later estimates that 23% of US desktop ChatGPT ads placed between August 15 and August 30, 2026, use the format.
  • August 17, 2026 - Automatic advanced matching becomes the default setting for existing ChatGPT web pixels.
  • Before end of August 2026 - ChatGPT ads reach 31 European markets on the Free and Go subscription tiers, the platform's largest single expansion.
  • August 31, 2026 - Digiday reports, and PPC Land covers, that ChatGPT's advertising business reached a $1 billion annualized revenue run rate in under 200 days.
  • September 1, 2026 - Sensor Tower publishes "ChatGPT's Ads Business Gains on Rising Density and a Broadening Advertiser Mix," documenting the shift in advertiser mix toward financial services and other verticals.

Summary

Who: OpenAI, operator of ChatGPT's advertising network, and Sensor Tower, the market intelligence firm that published the analysis, affecting advertisers, media planners and marketers evaluating conversational AI as an ad channel.

What: Sensor Tower found that ChatGPT's advertising business reached a $1 billion annualized revenue run rate, that ad density per user rose 163% between April and August 2026, and that financial services advertisers grew from a single top-100 spender in April to four of the top ten spenders by August, as shopping's share of total US ad spend fell from 37% to 21%.

When: The report was published September 1, 2026, covering data trends from April through August 2026.

Where: The findings cover ChatGPT advertising activity in the United States, drawn from Sensor Tower's mobile and desktop measurement panel.

Why: The shift signals that ChatGPT advertising has moved beyond its early retail-dominated advertiser base toward more regulated categories that typically require stronger measurement and compliance infrastructure before committing budget, a development that coincides with the platform's rapid geographic expansion and its crossing of the $1 billion annualized revenue threshold.