ChatGPT Ads only learns from the conversions you send it

ChatGPT visits can land in the wrong row

Since 31 August 2026, businesses in the Netherlands and 30 other European markets can buy ads in ChatGPT themselves. Only people on the Free and Go plans see them; Plus, Pro and Enterprise stay ad-free. Measuring those ads is harder than setting them up.

Where ChatGPT visits show up in your analytics

Since May 2026, GA4 has a default channel called AI Assistant. A visit lands there when its referrer matches Google's list of AI assistants, which names ChatGPT, Gemini, Deepseek, Copilot and Grok as examples.

That only works when a referrer arrives. A visit from the ChatGPT app, an in-app browser or a pasted link can come without a referrer or a tag, and GA4 then still files it under Direct.

Tags have a trap of their own. When a link carries UTM parameters, GA4 takes the source from them, and a missing utm_medium shows up as (not set). A visit that matches no channel rule can end up in Unassigned.

So the same kind of visit can show up as AI Assistant, Direct or Unassigned. A visit with neither a referrer nor a tag carries nothing to recover, for any script, Sightwick's included.

Free citation or paid ad?

ChatGPT adds utm_source=chatgpt.com to the links it sends from its search results. The tag sits in the URL itself, so it still identifies ChatGPT when the referrer is lost. It also means every free citation already carries a ChatGPT label.

A click on a ChatGPT ad carries something else: a click identifier called oppref, added to the landing page URL.

If you tag your ads with utm_source=chatgpt.com as well, free and paid visits share one row in your reports, and your ads get credit for traffic they never bought. ChatGPT Ads lets you add your own parameters to the landing page URL, with macros such as {campaign_id} and {ad_id}. Use a source of your own there, with a paid medium such as cpc, and never chatgpt.com.

Your setup decides what ChatGPT Ads sees

ChatGPT Ads hears about conversions in two ways: OpenAI's measurement pixel on your site, or its Conversions API, which your server calls. It only counts the conversions that one of them reports, and its reporting has rules of its own:

• The Conversions figure in Ads Manager counts conversions after a click. View-through conversions, where your account has them, use a fixed one-day window after an impression, are reported separately and do not count toward CPA, bidding, billing or conversion optimisation.
• Reports use a click window of 7, 14 or 30 days, 30 by default, and date a conversion by the day of the ad click unless you switch to conversion time.
• ROAS is purchase value divided by spend, so the value of a lead does not show up in it.
• A conversion-optimised campaign takes exactly one standard event as its goal, such as order_created or lead_created. Custom events cannot be that goal, and the feature is in open beta.

Pixel, Conversions API, or both

OpenAI's documentation calls the Conversions API "a more reliable tracking source than the pixel alone". That is OpenAI's own claim.

OpenAI's pixel reads oppref from the landing page URL and keeps it in a cookie on your domain for 30 days. It does so while measurement consent is on, which is the pixel's default until your site switches it off.

The Conversions API does not pick up oppref by itself. An order or a quote request three pages after the landing, or a day later, reaches ChatGPT Ads without its click ID unless something kept it.

If you use both, OpenAI counts a conversion once only when both carry the same event ID; the first one to arrive wins.

What Sightwick can close

Sightwick measures on your own site and connects to ad platforms server-side.

It recognises a ChatGPT visit by its referrer, by the Sightwick tag on your ad link, or by the ChatGPT Ads click ID. A visit with the click ID or with that tag goes into a channel of its own, Paid Assistant. A free citation tagged utm_source=chatgpt.com is never credited to ChatGPT Ads in Sightwick's reports.

It keeps the click ID from the landing page. A conversion later in the same visit carries it, and when the ad click was that browser's first visit to your site, so can a conversion up to 30 days later.

It can send conversions server-side to OpenAI's Conversions API: orders as order_created, quote, demo, contact and callback forms as lead_created, trial sign-ups as trial_started and bookings as appointment_scheduled, with value and currency where there is an amount. With each one goes what links it to the click: the click ID, OpenAI's own browser cookie when present, a hashed email address or phone number when your site supplies one, the IP address and the user agent.

Nothing goes to ChatGPT Ads unless the visitor accepted marketing and analytics cookies. By default, at most one conversion per visit goes to your ad platforms, the same rule as for Meta and Google Ads, and scroll depth, time on page and bounces do not go at all. Events OpenAI would refuse, such as ones older than seven days, are held back before sending, because at OpenAI one bad event fails its whole batch.

On a Shopify store

Orders can go to ChatGPT Ads server-side as order_created, with their value and only with consent. An order gets the click ID Sightwick kept from the visitor's latest visit, by the same rules as above, if that visit had marketing and analytics consent too. Otherwise, or if Sightwick never saw the visitor before checkout, OpenAI has to match it on the hashed email address, IP address and user agent.

What connecting takes

You paste the pixel ID and a Conversions API key from your own Ads Manager into Sightwick, and a test button checks them with OpenAI without storing anything. How it works in the product is on ChatGPT tracking.

What Sightwick can't do

• A visit with neither a referrer nor a tag is invisible to Sightwick too.
• When a visitor declines cookies, the landing is still counted by source on your own dashboard. The conversion that follows gets no credit, and nothing about it goes to OpenAI.
• The click ID is kept in the browser's local storage, which Safari clears after seven days of browsing without the visitor interacting with your site. And if the ad click was not that browser's first visit to your site, its click ID only reaches a conversion in that same visit.
• A send that fails is not retried. The last error shows on the Delivery screen.
• Sightwick does not show ChatGPT Ads' own conversion numbers or spend. Conversions travel one way, from your site to OpenAI.
• Organic ChatGPT traffic has no channel of its own in Sightwick. With a referrer it lands in Referral, with only the tag in no channel at all (shown as Unmapped), both with the source chatgpt.com. GA4's AI Assistant channel is more specific here.
• Stape, Tracklution and TrackBee already offer a connection to ChatGPT Ads; Sightwick came later.

Five checks before you spend

1. Click your own ad and check that oppref is still on the landing page URL. Redirects, caches and plug-ins that strip parameters can remove it.
2. Tag your ads with a source of your own and a paid medium, never chatgpt.com. In Sightwick, use the tag it gives you.
3. Report each conversion once: one sender, or the pixel and the API with the same event ID.
4. Pick the one standard event you optimise for, such as order_created for a shop or lead_created for leads. Custom events cannot be that goal.
5. Compare numbers only when the click and view windows and the date basis match.

For visits that carry a sign of ChatGPT, Sightwick tells you which conversions came from an ad and which came free. It does not add conversions of its own, but it can hand your conversions to ChatGPT Ads with the click ID attached wherever it survived.