How do I measure traffic, signups, and revenue coming from AI search?

In GA4, build a custom channel group (or use the newer built-in AI Assistant channel) matching referrers like chatgpt.com, perplexity.ai, and gemini.google.com, then compare conversion rates rather than raw sessions. Expect small volume that converts several times better than organic: studies range from 31% higher for ecommerce to 6x or more for SaaS signups. Know that a large share of AI-influenced visits arrives stripped of referrer data and lands in Direct, so whatever you measure is a floor, not the whole story.

A quick orientation. The real value is below: resources worth your time, from people who've actually done it.