The U.S. numbers behind the first ChatGPT ad benchmark
According to a working paper under review by Maximilian Kaiser and Christian Schulze, a visit from a paid ChatGPT ad in U.S. traffic generated $0.89 in tracked revenue. A visit from a paid Google search ad generated $2.45. The study follows 102 advertiser sites with full sales tracking as OpenAI rolled out ads country by country.
Conversion tells the same story: 0.37% for ChatGPT ad visits compared with 1.17% for paid search. Even when the authors compared the same websites, controlling for device and week, the gaps remained.
A few advertisers carried nearly all the results
Among 87 advertisers that bought both ChatGPT ads and paid search, 84 earned less from a ChatGPT ad visit than from search. Of those, 73 recorded zero sales across 18,726 visits. The other 14 produced all 570 ChatGPT ad purchases. One advertiser alone accounted for 66% of purchases across the full 102-site sample; remove that account and the performance gaps widen.
What a ChatGPT click is really worth
The authors use paid search as a benchmark to calculate a parity price: the cost per click at which a ChatGPT ad click returns the same tracked revenue per dollar as search. Their estimate is about $0.26 per click, with resampling putting it between $0.05 and $0.57. The largest publicly known account paid $1.72 per click, more than six times parity. OpenAI’s own basics page recommends starting CPC campaigns with a max bid of $3 to $5.
For your account, run the same math:
- Divide ChatGPT ad revenue per visit by paid search revenue per visit.
- Multiply the result by your paid search CPC.
- Treat that number as your starting ceiling, not a target.
Keep in mind parity assumes similar margins and only captures the tracked visit. The paper found no detectable lift in other channels after the first ChatGPT ad click, but it could only rule out large increases.
The organic side is holding up, mostly
For 1,898 sites, unpaid ChatGPT referrals fell an estimated 5.9% in the first 13 weeks after ads launched, relative to organic search and compared with the EU. Adjusting for faster ChatGPT adoption in North America, the decline lands around 7.2% to 8.4%. Organic conversions barely moved: −0.02 percentage points from a 2.21% baseline.
Don’t benchmark on vendor stories alone
OpenAI has shared an advertiser hitting 3x ROAS over 28 days, and DoubleVerify reported Weight Watchers’ attributed CPA came in 15.3% below benchmark. Those are useful signals, but the paper’s data and those metrics are not the same comparison.
Also filter ad-review crawler visits from your analytics before judging paid ChatGPT sessions; OpenAI notes crawlers can land with tracking parameters and get flagged as paid traffic.
The paper ends Aug. 22. OpenAI has since expanded ChatGPT Ads to 89 countries and says more than 100,000 advertisers have run campaigns. The early U.S. benchmark is a reason to test, not a reason to copy someone else’s bids.
Source: Search Engine Journal
