Attribution Window

An attribution window (or conversion window) is the period after a user interacts with an ad during which a resulting conversion is credited to that ad. For example, a 7-day click window credits the ad for any conversion within 7 days of a click. It defines how long the platform 'remembers' an interaction when assigning conversion credit.

A click-through window credits conversions that happen after a user clicks the ad (e.g. 7-day click). A view-through window credits conversions after a user merely sees the ad without clicking (e.g. 1-day view). Click-through is a stronger signal of influence; view-through captures the assist of being seen but credits more loosely. Platforms often combine them (e.g. 7-day click, 1-day view).

Longer windows credit more conversions to the ad, so they inflate reported conversions and ROAS relative to short windows — the same campaign 'looks' better on a 28-day click window than a 1-day. Including view-through credits even more. This means you can't compare results across different windows, and a window that's too long may credit conversions the ad didn't really drive.

Match it to your typical purchase cycle and compare consistently. Short windows (1-day) suit impulse purchases and conservative measurement; longer windows (7- or 28-day click) suit considered purchases with longer decision times. Whatever you choose, keep it consistent across campaigns so results are comparable, and be aware that longer/view-through windows credit more loosely — validate against incrementality where stakes are high.

Largely because of attribution windows and models. A platform may use a 7-day click + 1-day view window and credit itself for conversions your last-click analytics attributes elsewhere, so the same conversions get counted differently (or double-counted across platforms). Differing windows, view-through inclusion, and cross-device tracking all create gaps. Reconcile by aligning windows where possible and treating platform numbers as one input, not ground truth.