Attribution Window

The attribution window is the rule that decides how long after someone sees or clicks your ad a sale still gets credited to that ad.

Say someone clicks your ad on Monday but only buys on Thursday. Should Meta call that a sale from the ad? The attribution window is where that answer is set. Meta's default is 7-day click and 1-day view, which means a sale counts if the person clicked within the last 7 days, or simply saw the ad without clicking within the last 1 day.

Why this quietly flatters Meta. A longer window catches more sales, so the same campaign looks better on a 7-day window than on a 1-day one, even though nothing about the campaign changed. The number moved, not the reality. When someone shows you a ROAS, the first question is which window it was measured on, because a 7-day-click ROAS and a 1-day-click ROAS are not the same number.

Click versus view is the bigger deal. A click means they actually tapped your ad on the way to buying. A view means they saw it, did nothing, and bought later anyway, and Meta still claims the credit. View-through sales are the softest kind, the ones most likely to have happened without the ad at all. If you want the honest read, lean on click attribution and treat view-through as a maybe.

There is no single right window. Short windows undercount real, ad-driven sales that took a few days to decide. Long windows overcount sales that would have happened anyway. The one rule that saves you: pick one window and compare every campaign on that same window, so you are at least measuring with one ruler. And when the window's number and your bank disagree, the bank wins.

The attribution window does not change how many sales you got. It only changes how many Meta gets to claim.