What is an attribution window?
Nicklas Segatz Mortensen · Growth Hacker · Fractional CMO · Meta Ads Nerd · 8 July 2026 · 4 min.
Definition
An attribution window is the time period after a click or view within which a subsequent conversion is credited to the ad. Meta's default is 7-day click and 1-day view.
Also called: Attribution Window, Conversion window
Sådan virker det
Attribution fordeler æren for ét salg ud på de touchpoints, kunden mødte. Last-click giver alt til det sidste — de øvre kanaler ser svage ud. Ingen model er sand; totalen (MER) og inkrementalitet afgør sandheden.
01Why the window inflates the number
With a 7-day click / 1-day view window, Meta takes the credit if someone clicks and buys within a week — or simply sees the ad and buys within a day. View-through conversions are especially generous: many of them would have happened anyway. The wider and more inclusive the window, the more the attributed ROAS gets inflated.
Two accounts with identical results can report wildly different ROAS purely because of the window setting. And because each platform measures in its own silo with its own window, the sum of every channel's attributed revenue often exceeds the actual total.
Frequently asked questions
What's Meta's default attribution window?+
7-day click and 1-day view. That means purchases within seven days of a click — or a single day after just an impression — are credited to the ad, which systematically inflates the attributed ROAS.
Which window should I use?+
Pick one consistent window to compare over time, so trends are real. But never make budget decisions on the attributed number alone — use MER and incrementality tests for the final verdict.
Related terms
Glossary
What is attribution?
Attribution is the method that distributes the credit for a conversion across the touchpoints the customer met along the way. The model decides which channel gets the credit — and therefore where budget flows.
Read the entry →Glossary
What is incrementality?
Incrementality is the added effect a marketing effort creates: the sales that happened only because the ad ran. Sales you'd have gotten anyway aren't incremental — whatever the platform credits.
Read the entry →Glossary
What is MER?
MER (Marketing Efficiency Ratio) is your total revenue divided by your total marketing spend across every channel. It ignores the platforms' own attribution and shows how efficiently the whole marketing machine is working.
Read the entry →
Nicklas Segatz Mortensen
Growth Hacker · Fractional CMO · Meta Ads Nerd at Oaksmond
Growth hacker and fractional CMO with 10+ years' experience and hundreds of millions in managed ad spend behind him. Background from larger Danish and international scale-ups, and from the agency world.
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