A public index of which products ChatGPT and Perplexity recommend when buyers ask buying questions — measured weekly, published with the method.
Perplexity answer overlap, −3.7 pt since round 10
Scanned 19 October 2026. 135 samples from Perplexity, round 11. AI Customer Support for Ecommerce; short ink tick: round 10; 3 days since previous round. All figures measured. Methodology v2026-09-29.1.
Round 11 landed this morning. Perplexity now agrees with itself on 62% of our AI-support questions, down from 83% a week ago; ChatGPT slipped to 77%, from 82%. One engine is still making up its mind.
ChatGPT answer overlap, +4.0 pt since round 10
Perplexity 69%, −3.0 pt
Widest engine split in the top 5: Brevo, ChatGPT 45% vs Perplexity 27%.
Scanned 19 October 2026. 204 samples across ChatGPT and Perplexity, round 11. Answer overlap per engine; short ink tick on each arc: round 10; gap in percentage points from unrounded rates, shown where 10 or more; 3 days since previous round. All figures measured. Methodology v2026-09-29.1.
Perplexity answer overlap, −3.7 pt since round 10
ChatGPT 77%, −2.6 pt
Widest engine split in the top 5: Help Scout, ChatGPT 10% vs Perplexity 27%.
Scanned 19 October 2026. 270 samples across ChatGPT and Perplexity, round 11. Answer overlap per engine; short ink tick on each arc: round 10; gap in percentage points from unrounded rates, shown where 10 or more; 3 days since previous round. All figures measured. Methodology v2026-09-29.1.
65 question pages and 246 product pages, all free. How we measure
Three minutes to read, every number labelled.
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Perplexity and ChatGPT were asked the same 20 shopping questions. They named 66 brands between them and agreed on 15 — an overlap of 0.19. On the four questions that named brands themselves, agreement was total; on the open-ended ones it was close to zero.
Shoppers increasingly ask AI what to buy. Here are three practical ways to check whether ChatGPT, Perplexity, and Gemini recommend your Shopify store — and the exact fixes if they don't.
A practical, do-this-then-that checklist to make your Shopify store visible to AI assistants — crawler access, structured data, content patterns and measurement.