Short answer: Meta’s attribution setting controls how long after someone clicks or sees your ad a conversion can still be credited to it. The default for most conversion campaigns is 7 day click and 1 day view, and video ads can also count engaged views. The setting changes both what you see in reports and what the algorithm optimises toward. That is why Meta’s numbers rarely match Shopify or GA4, and why you should compare channels on total sales, not on platform reported ROAS alone.
What an attribution window is
An attribution window is the time between a person interacting with your ad and converting, during which Meta will credit the ad.
| Setting | Counts a conversion when someone |
|---|---|
| 1 day click | Clicked the ad and converted within 1 day |
| 7 day click | Clicked the ad and converted within 7 days |
| 1 day view | Saw the ad without clicking and converted within 1 day |
| 1 day engaged view | Watched at least part of a video ad and converted within 1 day |
You choose the setting at the ad set level when you create it. You can also compare other windows in reporting with the Compare attribution settings option.
Why it affects optimisation, not just reporting
Meta uses your attribution setting to decide which conversions count when it learns who to show ads to. A 7 day click setting tells the system to find people who buy within a week of clicking. A 1 day click setting focuses on people who buy quickly, which can suit impulse products but gives the system less data.
Why Meta never matches your store or GA4
- View through conversions: Meta counts some sales from people who saw but did not click. GA4 does not.
- Different models: GA4 uses data driven or last click across channels. Meta only sees its own ads.
- Cross device: Meta can connect a phone ad view with a laptop purchase for logged in users.
- Modelled conversions: with privacy limits, part of Meta’s numbers are statistical estimates.
- Time zone and date of credit: Meta credits the conversion to the date of the ad interaction.
None of these is wrong. They answer different questions.
How to choose your setting
- Most eCommerce brands: keep 7 day click and 1 day view, the default, and check sales in your store.
- Brands worried about over counting: compare results with 7 day click only in reporting. If view through conversions are a large share, test a click only setting.
- Lead generation with fast decisions: 1 day click or 7 day click can both work. Judge on qualified leads in your CRM.
- Video heavy accounts: look at engaged view conversions separately so you understand their share.
How to measure true impact
- Compare total revenue or leads before and after big budget changes.
- Track MER (total revenue divided by total ad spend) alongside platform ROAS.
- Run a conversion lift or geo holdout test when spend is large enough.
- Use the Conversions API so Meta receives more of your real purchases.
Frequently asked questions
What is the default attribution setting in Meta Ads?
Does the attribution setting change who sees my ads?
Why does Meta show more sales than Shopify?
Should I remove view through attribution?
What is engaged view attribution?
Who can fix my Meta Ads tracking and attribution?
Want numbers you can trust?
I can align Meta, your store and GA4 so you can judge ads on real sales. See my Meta Ads management and web analytics services, or request a free ads audit. Also read ROAS vs MER vs CAC and Meta Pixel vs Conversions API.