Attribution Glossary

Attribution

The rule that decides which ad gets credit for a sale.

Attribution model

A specific rule for splitting one order's credit: last click, first click, linear, and so on.

Attribution window

How long after a click or view a purchase still counts as that ad's.

ATT (App Tracking Transparency)

Apple's iOS permission prompt; most people decline, breaking in-app click to Safari purchase links.

Ad blocker

Browser software that stops tracking scripts loading, making the visit invisible to pixels.

Blended ROAS

All revenue over ad spend, new and returning customers mixed together.

Brand search

Paid search on your own brand name; usually the last click on demand created elsewhere.

CAPI (Conversions API)

Meta's server-to-server way of receiving purchase events with match keys.

Click ID (fbclid, gclid, ttclid)

The identifier a platform appends to a clicked link so a later purchase can be tied back.

Consent mode

Google's reduced tag behaviour when a visitor declines cookies; conversions are modeled or dropped.

Cross-device

Click on one device, buy on another; unlinkable by cookies, linkable by identity at checkout.

Data-driven attribution

A model that learns credit weights from conversion paths instead of a fixed rule.

De-duplication

Making sure the same purchase sent by pixel and server is counted once, usually by order ID.

Direct traffic

GA4's bucket for visits it cannot source; balloons when tracking breaks.

Enhanced conversions

Google's version of sending hashed customer data with a conversion to improve matching.

Event match quality (EMQ)

Meta's 0 to 10 score for how well a server event can be linked to a person.

First click

Attribution model that gives all credit to the first touch.

First-party tracking

Recording clicks and orders on your own domain rather than through third-party cookies.

Geo holdout

An incrementality test that pauses a channel in some regions and compares sales with the rest.

Halo effect

Sales a channel causes on other channels or platforms (e.g. TikTok driving Amazon), visible mostly in MMM.

Incrementality

Sales that would not have happened without the ad; measured by switching the ad off for some people.

iROAS

Incremental ROAS: incremental revenue over spend, from a test rather than from attribution.

ITP (Intelligent Tracking Prevention)

Safari's cookie limits; script-set cookies expire in 7 days or less.

Last click

Attribution model that gives all credit to the final touch before purchase.

Linear attribution

Equal credit to every touch on the path.

MER (marketing efficiency ratio)

Total revenue over total ad spend; cannot be gamed by attribution.

MMM (marketing mix modeling)

A statistical model estimating each channel's contribution from spend and sales over time.

Modeled conversions

Purchases a platform estimates it caused but could not observe; labelled, unverifiable per order.

New-customer ROAS

First-order revenue from first-time buyers over spend; the acquisition number.

Order-verified attribution

Attribution that starts from the store's order and cannot credit more than the order's value.

Overlap

Two campaigns or platforms each claiming the same order.

Performance Max

Google's automated campaign type that serves across Search, Shopping, YouTube and more, including brand terms by default.

Pixel

A script in the shopper's browser that reports events to an ad platform.

Post-purchase survey

A one-question 'how did you hear about us' on the thank-you page.

Reconciliation

Checking that channel revenue rows add up to store revenue.

Retargeting

Ads shown to people who already visited or bought; over-reports heavily under view-through.

Sendback

Sending verified conversions to ad platforms so their algorithms learn from real orders.

Server-side tracking

Recording events from your server rather than the visitor's browser.

Time decay

Attribution model that gives more credit to touches closer to the purchase.

View-through conversion

A purchase counted because the buyer saw an ad within a window, without clicking.