Thirteen Industries. One Pattern: The Biggest Brand Isn't Always the One AI Names.

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 thirteen published studies — 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. The world's largest luggage maker trails a newer challenger. 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 simply the brands with the most revenue, capacity, or distribution.

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 studies below each rank a category, name the winners and the brands falling behind, and lay out the playbook. Start anywhere.

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.