Which AI answers send you paying customers

ChatGPT, Perplexity, Gemini and Claude now send real visitors to small products. Most analytics dashboards still file those visits under "direct" or "referral" and stop there. The question a founder cares about is narrower: did anyone who came from an AI answer pay?

This post shows how to answer it with data you already have.

How AI answers show up in your traffic

Each assistant leaves a slightly different trace when someone clicks a link in an answer:

• ChatGPT adds utm_source=chatgpt.com to links it cites. The referrer is often empty, especially from the mobile app, so the UTM tag is the reliable signal.
• Perplexity usually sends a referrer from perplexity.ai.
• Gemini sends gemini.google.com as the referrer when it sends one at all.
• Claude sends claude.ai.
• Copilot sends copilot.microsoft.com.

If you only look at referrers, you will miss most ChatGPT traffic. Check the landing URL's query string as well, and keep it before your router strips it.

Counting the visit is the easy half

A visit from Perplexity is nice to see. A payment from someone who first arrived from Perplexity tells you where to spend next week. To get there you need three things joined together:

1. The first source you saw for a visitor, stored when they land (a first-party ID works; you don't need a cookie banner for this if you use a daily rotating hash and keep no personal data).
2. The moment that visitor becomes a person: a signup, a waitlist form, or a checkout with an email.
3. The payment, which arrives later from Stripe, Razorpay, Cashfree, Paddle or whichever provider you use, through a webhook.

Join 1 to 2 on the visitor ID, then 2 to 3 on email or customer ID. Now each payment has a source, and "AI answers" becomes a row with money next to it.

What to do with the number

On the Formfox demo shop, ChatGPT sent 6 paying customers worth $84.02 in October and Perplexity sent 3 worth $33.51. Gemini and Claude sent visits but no payments. That's a small slice of revenue, and it's still useful, because it tells you which pages the assistants are citing.

Open the landing pages for those paying visitors. They are usually comparison pages, pricing pages and plain how-to pages with a clear answer near the top. Write more of those. Keep prices in text, not images, so an assistant can quote them.

The short version

• Look for utm_source=chatgpt.com in landing URLs, and referrers from perplexity.ai, gemini.google.com, claude.ai and copilot.microsoft.com.
• Store the first source per visitor and join it to signups and payments.
• Rank AI sources by money, then study the pages they landed on.

Zerotoco does this join for you: paste one line on your site, connect your payment provider, and AI answers show up as their own sources in Today, with the money they sent. You can try it free on one site.