A report using Similarweb panel data found that ChatGPT's ad click-through rate topped 1% in four markets - but the US was not among them. The finding is interesting not because it tells us much about paid advertising mechanics, but because of what it implies about the underlying user behaviour driving those numbers.
For anyone building an AEO or GEO programme, the more relevant question is this: if ad engagement varies this significantly by market, what does that tell us about how differently users in those markets are engaging with AI search overall? That is where the real strategic implication sits.
Market-Level Variation Is Not a Footnote
The US has been the primary testing ground for ChatGPT's ad product and, based on available usage estimates, may have among the largest ChatGPT user bases. The fact that ad CTR there sits below 1% - while other markets clear that threshold - points to meaningful differences in how users approach the platform depending on where they are.
Users in markets that hit higher CTRs may be arriving at ChatGPT with more transactional intent. They may be earlier in their adoption curve, meaning commercial content feels less intrusive. Or the advertiser mix in those markets is better matched to what users are asking about. Probably some combination of all three.
The practical implication for AEO: if you are trying to earn organic citations and recommendations from ChatGPT, you should not assume a single content strategy performs equally across markets. The signals ChatGPT uses to surface recommendations - authority, relevance, entity clarity - will interact differently depending on what users in each market are asking and how they are asking it.
What High Ad CTR Actually Signals About Organic Opportunity
When ad CTR is high in a given context, it usually means user intent is more action-oriented. People click ads when they are looking for something specific and the ad matches that need. A 1%+ CTR in AI search - a relatively new commercial format - suggests those users are in a mode where they want to act, not just gather information.
That is directly relevant to organic AEO strategy. If users in certain markets are engaging with ChatGPT at a more transactional level, they are also more likely to follow through on organic recommendations. A citation or recommendation in a response to a commercial query is worth considerably more than one in a purely informational exchange.
The report also noted that the top ChatGPT advertisers changed frequently. That instability in the paid layer is actually an argument for investing in organic AI visibility. Brands that earn consistent citation through structured content, strong entity signals and credible third-party mentions do not lose their position the moment a competitor outbids them.
The Advertiser Churn Problem Has an Organic Equivalent
Frequent turnover among top advertisers in a new ad format is normal. Brands test budgets, pull back when results are unclear, and cycle in and out. The same instability happens in AI organic visibility, but for different reasons - a model update, a change in how queries are clustered, or a competitor publishing better-structured content can shift who gets cited.
The brands that hold position across those shifts are the ones that have done the underlying work: clear entity definitions across the web, schema that makes their products and services legible to AI systems, content that directly answers the questions being asked rather than content written around keywords.
This is why AEO programmes need to be treated as ongoing infrastructure rather than a one-time content project. The advertiser churn data from ChatGPT is a proxy signal for how volatile AI-mediated visibility is across the board. Organic positions are more durable, but only if the foundations are maintained.
Geography Should Shape Your AI Visibility Priorities
Most brands running AEO programmes are doing so with a single content strategy applied globally. The ChatGPT CTR data is a reminder that AI search behaviour is not uniform. Perplexity, ChatGPT and Google AI Overviews all draw from different user bases with different query patterns, and those differences compound when you factor in market geography.
If your business operates across multiple markets, it is worth analysing your AI-referred traffic - where it is coming from, what queries are driving it, and whether the referral-to-conversion rate differs by geography. Most GA4 setups will not surface this cleanly, but combining source/medium data with landing page analysis and CRM attribution can start to reveal patterns.
For UK-focused businesses, the specific markets that cleared 1% ad CTR in this report are not named in the available data. But the principle holds: if ChatGPT engagement is higher in certain regions, those are the markets where your AI-optimised content is most likely to drive a measurable outcome. Prioritise accordingly.
Measuring AI Search When Paid and Organic Blur
One of the more subtle challenges the ChatGPT ad rollout creates for measurement is that it complicates how AI-referred traffic is categorised. Users who click an organic citation from ChatGPT and users who click an ad may arrive via the same referral path in your analytics. Without careful UTM discipline on the paid side, the two can be conflated.
This matters for anyone trying to attribute revenue to AI search. If you are seeing ChatGPT referral sessions in GA4 or your CRM but cannot separate organic citations from paid clicks, your AEO performance data is unreliable. The fix is straightforward in principle - ensure all ChatGPT ad landing URLs are tagged with campaign parameters - but it requires coordination between whoever manages the paid activity and whoever is reporting on organic AI visibility.
As AI search platforms add more commercial layers, clean attribution becomes harder and more important at the same time. The brands that will have an accurate picture of what AI search is contributing to revenue are the ones that treat measurement as part of the programme from the start, not something to retrofit once the traffic is already flowing.