The Reach–Click Divide: in ChatGPT's first nine ad markets, the places where ads reach the most users are the places where they get clicked the least. Six months in, advertisers are still testing.
ChatGPT ad reach vs. CTR by country. Each dot is one of the nine live ad markets. Left to right: share of ad-eligible users who saw at least one ad (Sep 2026). Height: all-time ad click-through rate (Mar 30–Sep 16, 2026). The US, UK, Canada, Australia and New Zealand reach the most users but get the fewest clicks.
Reach (slide 8) is the share of eligible ChatGPT users who saw at least one ad in Sep 2026. CTR (slide 10) is all-time, Mar 30 to Sep 16, 2026. The two measures cover different periods. Markets that went live later have shorter CTR histories, which may favor them. Similarweb discloses shares only, not panel sizes. For context, LocaliQ puts the 2026 average search-ad CTR across industries at 6.64%, from advertiser campaigns rather than a panel.
Top ChatGPT advertisers by category: share of US ad impressions, top 10 of Graphite's categories, Mar 30–Aug 4, 2026, %
Slide 17. Top 10,000 US advertisers, classified into Graphite's taxonomy. Full category names: Retail & Consumer Brands, Business & Professional Services, Developer Tools & Infrastructure, Ecommerce & Website Platforms. Category leaders: Monday.com (B2B SaaS, 1,210 advertisers), Home Depot (retail, 1,510 advertisers), LegalZoom (professional services, 2,231 advertisers). These 10 categories add up to 67.9% (PPC.co sum); eight more are listed at 1.6% to 3.1%.
Top 10 ChatGPT advertisers worldwide, share of ad impressions, 2026, %
Slide 14. The slide's footnote describes a different measure (weeks in the top 10, May 4–Sep 14, 2026), so the exact window for these shares is unclear. Only Jotform and Resume.io held a top 10 slot in all 20 weeks tracked (slide 16).
Where ChatGPT ads appear in a conversation: share of ad impressions by conversation turn, all countries, Mar 30–Aug 23, 2026, %
Slide 13. A turn is one exchange (a user message and its reply). Turns 1–3 together hold 51%. Ads in turns 1–4 have 48% higher CTR than later turns, per slide 12.
ChatGPT ad creative testing: median distinct ads per advertiser, by impression-share rank, US, Apr 1–Aug 16, 2026
Slide 22. 400+ US advertisers. The deck prints each cohort's median impression share: 0.54% for the top 50, 0.04% for ranks 401–496. 19× is 191 ÷ 10 (PPC.co calculation).
ChatGPT ad landing pages per advertiser: share of all US advertisers vs. the top 50, Jul 19–Aug 15, 2026, %
Slide 25. 400+ US advertisers vs. the top 50 by impression share. 60% is 23% + 37% (PPC.co sum); the deck says 63% of the top 50 have 6+ pages. Shares for all advertisers add up to 101% because of rounding. The median advertiser runs 4 landing pages; category medians range from 1 (AI tools) to 30 (affiliate and comparison sites), per slide 30.
ChatGPT ads vs. Meta ads: ads live per advertiser, 10 advertisers active on ChatGPT, Meta and Google Search, trailing 28 days to Aug 2026
Slide 26 (Similarweb AI Ads, Meta Ad Library, Google Ads Transparency Center). Google Search still carries more ads than ChatGPT for 9 of the 10: Jotform 371, Attio 110, BestMoney 1,557, Resume.io 252, Envato 1,111, HubSpot 218, Monday.com 1,587, Cursor 204, Canva 942, Shopify 1,375.