Attribution Window
The attribution window is the number of days after an ad click during which a resulting order is still credited to that click. Amazon's default is 7 days for Sponsored Products; the choice of window directly changes reported ACOS.
The attribution window defines how long Amazon will keep crediting a purchase to a prior ad click. A shopper clicks your Sponsored Products ad on Monday and buys on Friday — under a 7-day window, that order is yours; under a 1-day window, it is not.
Defaults by ad type
| Format | Default attribution window |
|---|---|
| Sponsored Products | 7 days |
| Sponsored Brands | 14 days |
| Sponsored Display (clicks) | 14 days |
| Sponsored Display (views) | 14 days view-through |
| DSP | 14 days |
Reports let you switch the window for analysis (1, 7, 14, 30 days for SP). The marketplace billing logic is fixed at the format default.
Why the window choice matters
The window is not a passive setting — it determines the ACOS you read. Same campaign, same week:
- 1-day ACOS: 38%
- 7-day ACOS: 22%
- 14-day ACOS: 18%
Same truth, three numbers. Pick one window for all reporting and stay with it. Switching windows mid-quarter makes performance look like it changed when nothing changed.
Choosing a window
- Short consideration products (consumables, low-AOV staples): 1-day or 7-day. Most orders are same-session anyway.
- Long consideration products (appliances, electronics, gifts >€100): 14-day. Penalising the campaign for delayed conversion misrepresents the real funnel.
- Brand campaigns: 14-day. Brand discovery → research → return-visit purchase is the dominant pattern.
Attribution window vs. lookback window
These are different concepts and people confuse them constantly. See Lookback Window — that one defines how far back a report looks to find eligible clicks for orders in the period; the attribution window defines how far forward from a click a purchase can still be credited.
Common mistakes
- Comparing 1-day ACOS to a 14-day ACOS target. The numbers are not in the same units.
- Switching windows quarterly to "look better." Audit trails do not forget.
- Ignoring the window in cross-channel reports. A 14-day Amazon attribution next to a 30-day Google attribution will systematically double-count.