First-touch attribution

First touch attribution credits the introducer. A first-touch attribution model stores that introduction once. Last-click credits the closer, usually brand search or an email. Motif then ranks channels by the money that followed.

What gets stored

Precedence on the first event: utm_source and utm_medium, then a known ad-click id, then a normalized referrer host. Everything else is direct or unknown.

What never wins

Direct, unknown, and unattributed outcomes stay on the chart. They cannot take the recommendation. The model cannot invent a ranking the arithmetic does not support.

AI assistants are a channel

A click whose referrer is a dedicated assistant host (chatgpt.com, claude.ai, perplexity.ai, gemini.google.com, copilot.microsoft.com, grok.x.com, and the rest Motif classifies) is first-touch ai_assistant. That is a person. GPTBot is not.

How Motif stores first-touch attribution

Capture the first event On arrival Motif stores utm_source and utm_medium if present, else a known ad-click id, else a normalized referrer host.
Never overwrite it Later visits, including brand search and Direct, do not replace the stored first touch.
Join Stripe to that touch Checkout, invoices, refunds, and cancellation point at the stored introduction, cohort-correct to the arrival window.