Attribution: how a signed case is credited

Attribution is the bookkeeping rule that credits each signed case to exactly one channel. By default, a case goes to the last paid click or tracked paid call in the 30 days before its lead’s first qualifying contact. Attribution says which dollars touched a case, not which dollars caused it; that takes a holdout test.

The default view: last paid touch

If there was no paid touch in the 30 days, the case goes to the last non-paid tracked source (organic search, direct, a referring site or an AI assistant), then to the self-reported source, and failing that to “source unknown”.

Why last paid touch: it is the rule the ad platforms bid on, so the report can reconcile to what each platform was told. It is bookkeeping, not proof, which is why every channel line shows its test status.

Two other views always sit beside it, never blended into it:

• First touch: the earliest tracked touch in the same 30 days.
• Self-reported source: intake asks “How did you hear about us?” and codes the answer: TV, radio, billboard, search, social media, AI assistant, a person’s recommendation, former client, attorney referral or other.

The report prints how often the default view and the self-reported source disagree.

Evidence order

When evidence conflicts, the first available item decides:

1. A platform click ID on the lead record, dated inside the window (Google GCLID, GBRAID or WBRAID; a Meta click or lead ID; a Local Services Ads lead ID).
2. A call-tracking match: a visitor-level number tied to a visit, or a number used by only one channel.
3. Form data in hidden fields: UTM parameters and landing page first, then the referrer.
4. The self-reported source.
5. Otherwise, source unknown.

Channel rules

• TV, radio and billboards never get click-based credit.
• Brand search carries the note “brand demand is partly created elsewhere; see the test status”.
• AI assistants get their own line.
• One credit per case. Channel totals plus “source unknown” equal total signed cases.

Lookback windows

A stage reached after a platform’s window is recorded but not uploaded, and the report prints the share of signed cases that fell outside each window.

Language

Each lead has one language: the firm’s required preferred-language field, set from the conversation. A blank field falls back to the language of the ad, page or line, and is flagged. Spanish results are reported two ways, by the language of the ad (what the money bought) and by the client’s language (who signed), because many Spanish speakers search in English and the reverse.

Cite as: The Probative Standard v1.0, Attribution. Last reviewed October 24, 2026, by the Probative editorial team.