Skip to main content

How Sealmetrics Attributes Conversions

Sealmetrics uses session-scoped last-click attribution: every conversion is credited to the traffic source of the session in which it fires, and the source of a session is determined by how that session started. There is no cross-session lookback window — by design, because linking sessions would require a persistent user identifier, which is exactly what Sealmetrics never creates.

How a session gets its source​

When a hit arrives, Sealmetrics decides its type (entrance vs. pageview) and its source using a strict priority cascade:

  1. Explicit UTM parameters in the landing URL (external arrivals only) — a new entrance with those UTMs.
  2. Ad click IDs (gclid, msclkid, ttclid, yclid, and others) — a new entrance attributed to the ad platform. A repeated hit with the same click ID does not create a second entrance (atomic deduplication), so a reload of a tagged landing page doesn't double-count.
  3. Payment-gateway referrers — returns from Stripe, PayPal, and other PSPs are recognized so that the payment provider never steals attribution from the real source.
  4. Passthrough referrers you configure — same behavior as payment gateways, for domains you designate (e.g. your SSO or external checkout).
  5. Referrer mappings (yours, then Sealmetrics' global list) — known domains classified into their channel.
  6. Any other external referrer — a new entrance attributed as referral traffic.
  7. Same-site navigation with an active session — a pageview that inherits the session's UTMs and source.
  8. Same-site navigation with no active session — a "rejoined" entrance (see Rejoined Traffic).
  9. No referrer, no session — direct traffic.

Conversions inherit the session source​

A conversion fired during a session is attributed to that session's source — the most recent entrance. If a visitor arrives from Google Ads in the morning and converts within that session, Google Ads gets the conversion. If they come back later through a newsletter link and convert then, the newsletter gets it: the new arrival started a new entrance, and last click wins.

Two properties follow from this:

  • Last click, always. A new tagged arrival mid-journey (new UTMs or click ID from an external entry) starts a new entrance, and any subsequent conversion belongs to it.
  • No lookback window. Sessions are independent. A conversion today is never credited to a source from yesterday, because no identifier connects the two sessions. (GA4-style 30/90-day attribution windows require exactly the persistent identity Sealmetrics refuses to keep.)

The session window​

A session groups hits through a short-lived, context-derived marker with a ~2-hour inactivity window. It is not stored in the browser and cannot recognize a returning visitor — see What We Track for the privacy details. When the window lapses, the next hit starts a fresh entrance with fresh attribution.

Why last-click only​

Multi-touch models (linear, time-decay, data-driven) need the full journey of an identified user across sessions — a persistent identifier, consent banners, and all the data loss that comes with them. Based on our legal analysis, session-scoped last-click is the attribution model that works without consent, on 100% of your traffic. Attribution computed on all of your visitors beats a fancier model computed on the 40–60% who accept cookies.