New 5W research measured how 25 brands in each of five categories — pharma, home improvement, health insurance, travel, and fitness apps — surface inside the AI engines that now answer buyer questions. The finding is consistent: citation share is not market share.
Buyers no longer start in a search box. They start in a chatbox — asking ChatGPT, Claude, Perplexity, Gemini, and Google's AI Overviews what to buy, who to hire, which company to trust. The brand the engine names is the brand that enters the consideration set. The brand it skips never gets a chance.
5W built the AI Visibility Index to measure that surface category by category. This release covers five at once — and read together, they tell one story. The market leader is rarely the citation leader. America's largest airline by capacity ranks fifth in citations. The maker of the world's best-selling drug ranks fifth in its category. The hotel chain with the most U.S. properties barely registers. In every category, the AI answer defaults to the brands with the deepest editorial record, the strongest consumer consensus, and the clearest owned position — not the brands with the most revenue, the most capacity, or the most stores.
That is the opportunity. Capacity and market share are slow to move and expensive to buy. Citation share is built — in earned media, reference accuracy, and the structured, AI-retrievable record of who a brand is and what it leads. The five studies below each rank a category, name the winners and the brands falling behind, and lay out the playbook. Start anywhere.
"Across five industries the finding does not change. The brand that leads the market is not the brand AI names first — and the brand AI names first is the one that wins the buyer. Citation share is the new scoreboard. It is not bought with ad budget or capacity. It is built — in earned media, in accurate reference data, in the structured record of who you are. Build it before your category's buyers finish their next search."
Each study analyzes more than 60 real buyer prompts across six sub-categories of its market, running every prompt five times per engine in clean, logged-out sessions across ChatGPT, Claude, Perplexity, Gemini, and Google AI Overviews. Citation share is the estimated proportion of brand mentions a brand receives across all tracked prompts — the core ranking metric. Each study names the top 25 brands, the winners, the brands falling behind, the structural findings, and the playbook.