"A Customer Found Us Through ChatGPT": How to Measure AI Referrals

Why does AI traffic look so small in Google Analytics?

Analytics tools work out where a visit came from using two clues: the referrer (the page the visitor came from) and tags in the link, such as UTM parameters. AI tools don't always pass either one.

• Mobile apps often send no referrer. A tap from the ChatGPT or Gemini app can open in a browser with no trace of where it came from. Analytics files it as Direct.
• Copied links lose their origin. If someone copies your URL from an answer and pastes it later, it looks like a typed visit.
• Tags and referrers change. ChatGPT began adding UTM tags to more links in June 2025. In October 2026, several analysts reported a period where links in answer text arrived with neither a tag nor a referrer, sending those visits to Direct until a fix rolled out.
• Some visits land in the wrong channel. A visit tagged chatgpt.com with no medium often shows as Unassigned rather than in any AI channel.

What does GA4's AI Assistant channel count?

In 2026 Google Analytics added AI Assistant to its default channel group, with ChatGPT, Gemini and Claude among the examples. It's a good start. But it relies on the referrer, and Google hasn't published the full list of sources it recognises.

Two gaps to know about. Perplexity traffic has been reported landing in Referral rather than AI Assistant. And clicks from Google's own AI Overviews and AI Mode count as Organic Search, not AI Assistant, because they happen inside Google Search.

How do you set up AI tracking properly in GA4?

1. 1
   Create a custom channel group

   In GA4, go to Admin, then Data display, then Channel groups, and copy the default group so you can edit it.

2. 2
   Add an AI channel that matches on source

   Add a channel called AI Assistants with the condition: Session source matches regex, using the pattern below. Match on source only, so tagged, untagged and medium-less visits all count.

3. 3
   Move it above Referral

   GA4 applies channel rules in order. Put the AI channel above Referral and Unassigned, or those rules will claim the visits first.

4. 4
   Build a simple report

   Add a report of sessions, engaged sessions, conversions and landing pages for the new channel. Landing pages tell you which content AI is sending people to.

(^|\.)(chatgpt\.com|chat\.openai\.com|openai\.com|perplexity\.ai|gemini\.google\.com|claude\.ai|copilot\.microsoft\.com|deepseek\.com|grok\.com|meta\.ai)$|^(chatgpt|perplexity)$

Should you just ask customers how they found you?

Yes, and it's the single most useful thing on this page. Analytics will always undercount AI. A one-line question on your sign-up, enquiry or checkout form fills the gap.

• Make it optional and free text, or a short list that includes "ChatGPT or another AI assistant" as an option.
• Ask at the moment of conversion, when people remember.
• Review answers monthly next to your analytics. If 10% of new customers say AI but analytics shows 2% of visits, you know roughly how much is hidden.

Is AI traffic worth chasing if it's small?

Often, yes, because of who it brings. Someone who asked an assistant for a shortlist and then clicked through to you has already done their research. For many businesses these visitors convert better than the average search visitor. Compare conversion rates by channel before deciding it's too small to matter.

If the number is small because AI rarely mentions you, that's a separate problem. Our guides on why ChatGPT recommends a competitor and tracking brand mentions in AI cover what to do next.