ChatGPT topic ownership: SEO isn't enough

Only 15.2 percent of the ChatGPT topic categories examined had a clear brand owner, according to a Semrush analysis. In around 85 percent of categories, no brand dominated. Visibility in a single prompt also said little about whether a brand appeared consistently across related buyer questions. The findings show how unstable brand authority in AI search still is — and why classic SEO metrics alone do not explain topic ownership.

How Semrush defines topic ownership

Semrush defined a category owner as the brand with the highest share of mentions. That brand had to appear in at least four of five related prompts and lead the runner-up by at least five percentage points. The threshold is deliberately strict: the goal is not one-off visibility, but a recurring association between brand and topic area.

• Only 15.2 percent of the 1,094 categories met that standard.
• Another 31.2 percent had an emerging leader that appeared in at least three prompts but without the required lead.
• The remaining 53.7 percent were unsettled because no brand appeared in at least three of five prompts.

Most of the ChatGPT topic landscape therefore remains open. For marketers, that means many categories are not yet firmly occupied. At the same time, appearing in one prompt is not enough. Brands aiming for topic ownership must be present across several related buyer questions.

Popular topics, few clear owners

Semrush split categories into two groups by AI search demand. In the top half — topics with high demand — only 11.3 percent had a clear owner. In the bottom half, the share was 19 percent. Paradoxically, demand was highly concentrated: the top half accounted for 98 percent of the AI search volume in the sample.

Most of the ChatGPT demand Semrush tracked therefore sat in categories without a dominant brand. Exactly where search volume for generative answers is especially high, stable brand leaders are often missing. That intensifies competition but also creates opportunities for brands that systematically build topical visibility.

Classic SEO metrics only partly explain ownership

Traditional SEO strength did not reliably predict which brands owned ChatGPT topics. Semrush compared category owners with runners-up using branded search volume, organic traffic, and Authority Score. The results put the predictive power of individual SEO metrics for generative engine optimization into perspective.

• Owners led on branded search volume in 55.7 percent of comparisons.
• On organic traffic, the owner ranked higher in only 48.4 percent of cases.
• On Authority Score, the figure was 52.5 percent.

Only branded search volume reached statistical significance. Kevin Indig, founder of Growth Memo, put it this way: traditional SEO metrics are not enough to explain who owns a topic. They play a role, but there are additional factors. For SEO and GEO teams, that means organic rankings and domain authority remain relevant but do not replace a targeted strategy for brand mentions in AI answers.

Mentions matter more than citations

Ownership was measured by brand mentions in ChatGPT’s answer text, not by the links cited below. Mentions and citations often did not align. Only 21 percent of the most-cited domains in a category were also the most-mentioned brand.

That is a central difference from classic search. In organic search, backlinks and cited URLs are important signals. In ChatGPT, a domain can appear frequently as a source without the brand being named dominantly in the answer text. Teams steering AI visibility should therefore separate both layers: citation share and mention share. For topic ownership, the mention in the generated text is decisive.

Why topic-level visibility matters more

Semrush found that prompt-level visibility did not always carry across related buyer questions. A brand that appears for a definition question does not automatically appear for comparisons, alternatives, or buying decisions. Topic-level visibility is therefore more meaningful: it shows whether ChatGPT consistently associates a brand with a category.

In practice, measurement across prompt clusters is preferable to isolated single prompts. Typical clusters include definitions, comparisons, alternatives, use cases, and buying decisions. Only brands that appear in several of these question types approach true topical authority in AI search.

Stable leadership versus narrow leads

Clear category owners stayed in first place in 90.4 percent of month-over-month comparisons. Weaker leads changed much more often: in emerging and unsettled categories, the top brand switched in 1,950 of 5,470 comparisons. Narrow leads were less stable. When a top brand later lost first place, its typical prior lead was only 1.3 percentage points. When it stayed on top, the lead was 2.9 points — more than twice as large.

Semrush does not explain why leaders change. The data do show, however, that brands with a smaller lead are more likely to lose first place. For GEO strategies, that means a slim mention lead is not enough. Brands that want to secure ownership need recurring presence across prompt clusters and a measurable gap over competitors.

Study data basis

Semrush and Kevin Indig analyzed 1,094 U.S. categories in ChatGPT from January through June 2026 using the Semrush AI Visibility Toolkit. The dataset covered more than 50,000 brands, 220,000 domains, 600,000 citations, and 220,000 URLs. Each category included five prompts tied to common buyer questions. The study underlines that AI visibility is a category-level game. Teams that base ChatGPT visibility only on single prompts or classic SEO KPIs underestimate the dynamics of generative search.

For SEO teams, that means measuring topic ownership across prompt clusters, tracking mentions and citations separately, and weighting branded search more strongly than pure traffic scores. Narrow leads are volatile and must be actively expanded. Generative engine optimization complements classic SEO — it does not replace it.