Attribution Window.

An attribution window (also called lookback window) is the defined period of time after a user interacts with an ad within which a conversion is credited to that ad. If a user clicks an ad and converts within the attribution window, the ad platform claims credit for the conversion. If they convert after the window expires, the conversion is not attributed to that interaction.

Common Attribution Window Settings

Google Ads default: 30-day click-through, 1-day view-through. Meta Ads default: 7-day click, 1-day view. Email marketing typical window: 5-7 days after open or click. The appropriate window depends on the purchase consideration cycle — an impulse e-commerce purchase warrants a 7-day window; a B2B SaaS deal with a 90-day sales cycle may warrant a 90-day click window.

View-Through Attribution

View-through attribution credits a conversion to an ad the user saw but did not click — they were exposed to a display or video ad, then converted on a different channel later. View-through conversions are controversial: the causal link is weak and they are frequently used by ad platforms to inflate reported performance. Evaluating view-through conversions separately from click-through conversions provides a more honest performance picture.

Attribution Window and Platform Comparison

Comparing performance across ad platforms is difficult when attribution windows differ. Meta's 7-day click + 1-day view window claims credit for more conversions than Google Ads' 30-day click window for the same events — and different windows cause double-counting when the same user sees ads on both platforms. Using a unified attribution model (GA4 data-driven or a CDP) that doesn't rely on platform-reported conversions provides the most accurate cross-channel view.