What is Attribution window?
An attribution window is the period after someone clicks or views an ad during which a purchase is credited to that ad. Meta's default is 7 days after a click and 1 day after a view.
Each platform credits purchases inside its own windows, so one order can be claimed by Meta and Google at the same time. That is why platform totals often exceed store revenue.
Compare attributed results with orders your store recorded before moving budget.
Example
A shopper clicks a Meta ad on Monday, searches your brand on Google on Thursday and buys: both platforms can claim the order.