# What is Attribution Window?

What is Attribution Window? The period during which an ad platform 'credits' a sale to an ad shown. Meta default: 7-day click + 1-day view.

## How it works in practice

The attribution window determines how many sales each platform 'sees.' Meta with a 7-day window will see more attributed conversions than Meta with a 1-day window — the same reality, a different story. This causes Meta and Google to together 'report' double the actual number of your sales.

## Related metrics

- Attribution — the window is part of an attribution model
- ROAS — ROAS is directly affected by the attribution window
- MER — MER isn't affected by the window (based on actual revenue)
- Meta Ads / Google Ads — each platform has a different window

## Common misconception

'The attribution window is the truth.' No. A 28-day window means: 'a sale that happened 28 days after a click is credited to the ad.' But the customer also saw 5 other ads, searched Google, and got a newsletter. The window is arbitrary.

## How to fix it

Attribution window confusing you? (1) Compare Meta reports + Google reports — usually 150-200% of actual sales (double-counting), (2) Use MER — not window-dependent, (3) Shorten Meta's window to 1-day click for a more conservative picture, (4) Run an incrementality test — check what would happen without the ad.

## Real-world example

Cosmetics store: Meta reports 340 sales (7-day window). Google reports 180 sales (30-day). Combined: 520. Actual (from WooCommerce): 310 sales. Double-counting: 67%. MER: revenue $26K / spend $7.8K = 3.3 — sufficient for management decisions.

## Where to start

Understand each platform's attribution window before comparing them. Set a consistent window (1-day click) if you want to compare directly. For decision-making: MER beats platform-reported ROAS.

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Category: Analytics · From the [Jimmy OS KPI Glossary](https://jimmy-os.com/glossary/kpi.md) · Source page: https://jimmy-os.com/glossary/kpi/attribution-window