Tracking traffic and sales from AI assistants: a GA4 and Shopify set-up

"AI traffic" covers three different things: answers that name your brand, visits that arrive from an assistant, and orders from those visits. Each needs a different tool, and none of the tools sees the other two. Mixing them is how teams end up arguing about a number that measures something else.

Which tool measures which layer?

Adobe's forecast is a click number. In a September 2026 release, Adobe expects AI traffic to U.S. retail sites to rise 130% year over year this holiday season, and says it measures that traffic by shoppers clicking on a link. A brand can be named in many answers and earn few clicks, or the reverse.

Our own October 2026 numbers are about exposure, not clicks. OpenAI's API with web search (gpt-6-luna) linked 2.2 pages per answer across 800 answers, and 46.6% of those answers linked a page on an own-site match domain. Perplexity's Agent API with the Sonar model (perplexity/sonar) retrieved 27.3 source URLs per answer across 787 answers, and 62.0% of those lists held an own-site match. An own-site match is a domain whose first label equals a recommended brand's name; it misses country domains and other store names. These rates are across all brands recommended in October 2026, not a rate for any one brand, and include every prompt type. A linked or retrieved page is not a click, and nothing in the index counts clicks.

What do Google, Shopify and Bing document?

As of October 28, 2026, these are the help pages' descriptions; they can change.

Google Analytics 4

• The default channel group has an AI Assistant channel for visits from sources such as ChatGPT, Gemini, Deepseek, Copilot and Grok. A visit qualifies when its medium is exactly ai-assistant, or when the referrer matches a list Google does not publish.
• The channel excludes Google's AI Overviews and AI Mode. Google counts those in Organic Search.
• Perplexity is not named in the channel description. Google's separate custom channel group example does include it in a regex, so test it in your own data.
• Google says channel definitions may evolve as the market changes.

Google Search Console

• Sites that appear in AI Overviews and AI Mode are reported in the Performance report within the Web search type, mixed into overall search traffic. Google does not describe a separate AI view there.

Shopify

• Acquisition reports, including Sessions by referrer, cover sessions only and apply to the Online Store sales channel only. They show visitors, not converted sales or orders; the Total sales by referrer report shows sales.
• UTM dimensions show raw data from the session. Referring channel, referring medium and traffic type are standardized groupings.
• Sessions and visitors are counted with cookies, and a session ends after 30 minutes of inactivity.
• Shopify's help page says its session measurement rollout runs from September 21 to 23, 2026, and that its marketing channel dimensions changed on October 18, 2026. Shopify points to its article on comparing marketing channel data over time. Our own advice is to treat any comparison that spans those dates with caution.
• The Agentic section (Sales channels > Agentic) reports sales, orders, online store sessions and conversion for each AI channel you sell through, plus a total sales report. Sales data combines referral-based sales and direct checkout sales. It is not yet available for headless stores.

Bing Webmaster Tools

• The AI Performance report, in public preview as of October 2026, shows citations displayed as sources in AI-generated answers, cited pages, and grounding query phrases. Microsoft says the data is a sample of overall citation activity and that the totals do not indicate placement within an answer. The page does not describe click counts.

What we could not document. We found no first-party page we could open that lists the referrer or utm_source values that ChatGPT, Perplexity, Copilot or Gemini send. OpenAI's publisher FAQ, which search engines still describe as covering this, redirected to an unrelated help article when we checked on October 29, 2026. This post therefore gives no list of values. The next section builds the list from your own data, which is more reliable anyway because it shows what reaches your site.

How do you set up GA4?

1. Look before you build. Open Reports, Acquisition, Traffic acquisition and scan session source for assistant names such as chatgpt, openai, perplexity, copilot, gemini and claude. Note which channel each lands in.
2. Create the group. In Admin, under Data display, open Channel groups and create a new channel group. If you have none yet, it starts as a copy of the default group.
3. Add a channel named AI assistants with a condition on source that matches a regular expression. Google's example regex covers ChatGPT, Gemini, Microsoft Copilot and Perplexity. Its list of popular assistants also names Claude, which that regex does not name. A short version to adapt: chatgpt|openai|perplexity|copilot|gemini|claude. Check the matches for false positives, since a word like "gemini" can belong to unrelated sites. The word chatgpt also matches a source such as chatgpt.com, if that is what your reports show. If your copy of the default group already has an AI Assistant channel, either edit it or place your channel above it, otherwise the default channel takes the visits first. The reason to build your own is that the default list is not published and does not name Perplexity or Claude.
4. Order it above Referrals (and above Organic Search if needed). GA4 puts traffic in the first channel whose rule it matches.
5. Read it in the reports. Select the new group as the primary or secondary dimension in the user acquisition and traffic acquisition reports. Custom channel groups can be applied to reports retroactively, and a standard property can hold two of them.
6. Tag only what you control. A medium of exactly ai-assistant places a visit in the default AI Assistant channel. Use it only on links you place yourself, and check each program's rules before adding parameters to any link.

Then compare purchases by channel. The comparison tells you where converting visits came from; it does not tell you which assistant answer persuaded the visitor.

How do you set up Shopify?

1. Sessions. In your admin, go to Analytics, then Reports, and filter the category to Acquisition. Open Sessions by referrer and look at the referring channel and UTM source values for assistants.
2. Sales. Open the Total sales by referrer report (under Sales reports) for sales by referrer. Shopify's page says it shows the last interaction referrer, so a visit from an assistant followed by a later direct visit can be credited to Direct.
3. AI channels. If you sell through them, open Sales channels, then Agentic, and read sales, orders, sessions and conversion per channel. Shopify says the Shop app's sessions, referrals and sales are included.
4. Keep a change log of the Shopify rollout dates above, theme changes and new tags, so you can explain breaks in the series.
5. Do not force GA4 and Shopify to match. They count with different rules. Use GA4 to see where visits come from and Shopify to see what sold, and compare trends, not totals.

What can attribution not see?

• Exposure without a click. A named brand with no link, or a shopper who sees the name and searches for you later, shows up as search or direct traffic.
• Missing referrers. Google defines Direct as arrival by saved link or typed URL. A visit with no referrer and no tag has nothing to classify, so it falls there.
• Google's AI features. They sit inside Organic Search and the Web search type, so Google describes no way to split them out in these reports.
• Direct checkout. A sale completed inside an assistant may not create a session on your site, so Shopify reports sales and sessions separately.
• Prompts. No first-party report we found shows the question that led to a visit.

What should you track each month?

Keep the same questions and assistants each month so the exposure column is comparable, and attach an interval to it. The measurement method and the post on how many answers to trust cover that column. For how API sampling differs from what shoppers see, read API answers vs app answers.

Frequently asked questions

Why is my Perplexity or Claude traffic not in GA4's AI Assistant channel?

Google's channel description names ChatGPT, Gemini, Deepseek, Copilot and Grok, and its referrer list is not published, so test it against your own data. A custom channel group can cover the others. A visit that arrives with no referrer and no tag goes to Direct instead.

Does a link in an answer mean I will get clicks?

No. Only a link that is shown and clicked produces a visit. In our October sample OpenAI's API answers linked about 2 pages each, and Perplexity's source lists are pages its search retrieved, not pages every answer shows or uses.