Pfizer vs Merck
Pfizer leads Merck by 14.7 points on the Fameproof index, and wins 2 of the three models. Measured weekly: 24 prompts × 4 runs = 96 answers per model.
Questions about this comparison
Who do AI models mention more, Pfizer or Merck?
Pfizer. It scores 55.7 on the Fameproof index against 41.0 for Merck — a lead of 14.7 points, measured across Claude and ChatGPT and Gemini in the run of 26 October 2026.
How is the Pfizer vs Merck comparison measured?
Both are asked about with the same panel of category questions — never questions naming them — repeated on every model each week. The score combines how often each is named, how early in the answer, how much of the topic is covered and how consistent the result is.
Both are ranked on the Company AI Visibility board. Prominence reflects how early in an answer the model names them; mention rate is how often it names them at all. How the score is built.
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