A shopper asks ChatGPT which running shoe fits a wide foot, gets three names back, and buys from one of them. The store sees an order. It never sees the question. That text isn't in the referrer, isn't in the order payload, and OpenAI's checkout spec has no field to carry it. Analytics can say an order came from AI, and then it stops.
AskTrail asks the one person who still remembers. On the Thank-you page the buyer picks how they found the store. If the answer is an AI assistant, a second step asks which one, with seven offered from ChatGPT to Grok, and what they typed, in their own words. The answer is saved against the order. The order is tagged AI-influenced and AI-source:chatgpt, so it filters in the Shopify admin like any other tag.
Paid plans replay those questions. Growth runs 50 prompts a week through the OpenAI Responses API with web search turned on, records whether the store surfaced in the answer, and lists the brands that surfaced instead. Every Monday a report goes out with the week's questions and the edit worth making.
One limit worth saying out loud: an API answer is not identical to what a shopper sees in the ChatGPT app. Probe results show direction, not an exact rank.