Glossary
Attribution window
The period after an ad click or view during which a later conversion still counts for that ad. A conversion after the window closes goes to another source.
Also called: conversion window, lookback window
An attribution window answers one question: how long after someone sees or clicks an ad are we still willing to say that ad caused the sale?
Set it to one day and you undercount — the buyer who thought about it over the weekend is credited to whatever they touched last. Set it to ninety days and you overcount, crediting an ad that had nothing to do with a purchase three months later.
Two things make this harder than it sounds.
Every platform picks its own default, and they do not match. The same purchase can be claimed by two ad platforms and a web analytics tool at once, each one correct inside its own window. Totals that exceed actual revenue usually mean windows are being compared, not conversions.
Click and view windows are different settings. A view-through window credits people who saw an ad and did not click it, which is a much weaker signal and usually a much shorter window.
Changing the window does not change what happened. It changes what gets counted, and it is almost never retroactive — the numbers reported before the change stay as they were.
Do not confuse with
Close enough to get mixed up, different enough that the mix-up costs something.
- Cookie window How long a tracking cookie stays valid after a browser stores it. When the cookie expires, a returning visitor can no longer be linked to the earlier click.
- Last-click attribution A model that gives all credit for a conversion to the final click before it. It is the most common model and gives no credit to earlier ads in the journey.
- View-through conversion A conversion credited to an ad the person saw but did not click. The platform logged the impression, but your analytics did not, so the two reports differ.