Self-Serve B2B Software Tops ChatGPT Ads as Click Rates Double

The ten biggest advertisers in ChatGPT worldwide, by share of impressions, are monday.com, Jotform, Resume.io, Booking.com, Design.com, Cursor, ManageEngine, Shopify, HubSpot and Cloudflare. Seven of the ten sell business software, and you can start using nearly all of them before anyone from sales calls.

The ranking comes from the State of ChatGPT Ads report that Graphite, a search and growth agency, published with Similarweb on September 28. The full report is gated, so the detail here comes from PPC Land’s read of it. Graphite's public summary says click-through has doubled since ads launched in March and that 43% of ad-eligible US users have now seen one. PPC Land puts the worldwide gain at 112% between March 30 and September 16, with weekly click-through climbing from about 0.4% to about 1.0%. It reports B2B SaaS as the largest category, at 19.9% of US impressions across 1,210 advertisers.

ChatGPT Ads is already a B2B channel for software a buyer can sign up for in one sitting. OpenAI’s measurement is built to match that buyer. Sales-led teams that buy in now will pay for clicks that OpenAI's 30-day conversion window can't connect to pipeline. Their first ChatGPT Ads budget should go to measurement before media.

Graphite's own playbook says to test long sales cycles with caution

The report's authors draw the line themselves. "Top 10 advertisers all sell something buyable in one sitting," Graphite writes. Its recommended playbook tells advertisers to budget the channel like a test and lead with offers people can buy right away. It also says to approach long sales cycles carefully. The most-used landing pages are feature, pricing and product pages, the pages a self-serve buyer converts on.

The headline comparisons are narrower than they sound. The finding that half of top advertisers run more ads on ChatGPT than on Meta rests on a cross-channel sample of 10 advertisers. Nine of those ten still run more ads on Google Search than on ChatGPT. Similarweb discloses percentages and shares only, with no panel volumes, costs or conversions. A doubled click-through rate tells you people click, but it doesn't say what they bought.

OpenAI's ads business is large enough to take seriously anyway. The company said on August 31 that ChatGPT Ads had reached a $1 billion annualized run rate in under 200 days, with tens of thousands of advertisers.

OpenAI's conversion tools stop counting after 30 days

OpenAI's documentation shows what the channel was built to measure. Its conversion tracking guide sets a 30-day click attribution window and tells advertisers to use 30. Server-side events sent through the Conversions API must carry a timestamp from the last seven days. The standard events run from page views and trials to lead submissions, appointments and orders. Nothing in the standard list describes an opportunity or a closed deal. Advertisers can define custom events, but the 30-day window still applies.

For a self-serve product, that's enough, because the trial starts or the order goes through inside the window. A sales-led company is different. Its ad click turns into a demo request, then a discovery call, then an opportunity a month or two later. OpenAI's dashboard can credit the form fill and whatever the team reports back within 30 days of the click. Pipeline that opens after day 30 never gets credited to the ad.

Agencies are hitting the gaps already. Digiday reported on October 1 that Accuracast ran a UK lead-gen campaign where ChatGPT reported about 100 clicks against 20 in the agency's own tracking. Form fills showed zero conversions for two weeks before they registered. One executive told Digiday that clients spending $10 million a month on Google put less than $100,000 into ChatGPT. Some legal teams won't enable conversion tracking at all over OpenAI's data terms.

The early-mover case is real for teams that can measure it

Waiting has a cost. The auction opened in March, and Mile Marker's Monica Shukla told AdExchanger that clients see value in being early before the space gets commoditized. HubSpot, ManageEngine and Cloudflare are on the top-ten list, so established B2B vendors are spending.

Look at how those three sell, though. HubSpot has a free CRM, Cloudflare has a free plan. ManageEngine offers free trial downloads. Each one can count a signup inside OpenAI's window and watch it convert later in its own systems. Being early pays when you can read the result. A sales-led team without that entry point is buying position in an auction it can't score yet.

AI answer ads can also disappear. Perplexity stopped taking new advertisers in October 2025. ChatGPT's reach and run rate put it in a different position, so for ChatGPT the open question is measurement. .

What this means for sales-led B2B marketing teams

Start with the click identifier. OpenAI's measurement pixel reads an attribution value called oppref from the landing page URL and keeps it in a cookie for 30 days. Write that value onto the lead record in your CRM as a hidden form field, so you can join ChatGPT clicks to opportunities and revenue yourself, long after OpenAI stops counting.

Before launch, get legal to sign off on OpenAI's conversion terms, because the Digiday reporting shows that's where some tests stall. In the first two weeks, reconcile OpenAI's reported clicks against your own analytics and don't scale spend until the two agree.

Organic AI traffic got a small measurement upgrade the same week as Graphite's report. Around September 30, a user in r/SEO noticed Gemini adding UTM tags to the links it cites, and Google's John Mueller replied, "Nice. I see it too." Search Engine Journal covered it the next day and noted that Google hasn't documented when the tags appear. One commenter claimed the referrer survives mainly on desktop, so a lot of Gemini visits from phones have been landing in direct traffic. That's one person's report. If it holds, it explains why a tag matters even though GA4 already has an AI Assistant channel. That channel depends on the referrer and excludes Google's AI Overviews and AI Mode.

Then build the organic baseline next to the paid test. Report AI Assistant sessions in GA4 alongside visits tagged utm_source=gemini, and check which channel GA4 files the tagged sessions under before anyone puts them on a slide. Business of GTM has argued that the AI-shaped funnel already has numbers. Without that baseline, a paid test can take credit for traffic your cited pages were already earning.

If your product has a free tier or a trial, run that as the ChatGPT Ads offer instead of the demo form. If it doesn't, keep the test small and judge it by what shows up in your CRM.

On September 28, LiveRamp said advertisers can use its RampID identifier to bring CRM, loyalty and web data into ChatGPT Ads as custom audiences, for targeting or for suppression, starting in 11 markets it didn't name. That lets the CRM decide who sees the ads as well as score what they did, but OpenAI's help center requires 25,000 matched users before a custom audience can run. A self-serve vendor's signup base can clear that floor, while a sales-led team's list of target accounts usually can't. Business of GTM's later read of OpenAI's outside measurement partners covers who can now check those results independently.

My bet is that OpenAI will offer an attribution window longer than 30 days before it publishes a case study from a sales-led B2B advertiser.

Being early pays when you can read the result. A sales-led team without that entry point is buying position in an auction it can't score yet.

Write OpenAI's oppref click value onto the CRM lead record as a hidden form field, so ChatGPT clicks can be joined to opportunities and revenue after OpenAI's 30-day window stops counting.

By Business of GTM