An attribution window is the period of time after a click or a view during which a conversion is still credited to it.
Three windows are in play in a typical stack, and they are rarely the same:
| System | Typical window | Counts |
|---|---|---|
| Ad platform | 7 days click, 1 day view | clicks and views, including modelled conversions |
| Your first-party tracking | 7 days click | clicks only, observed |
| Your CRM | forever | whatever it decides |
Why it matters
The window decides which conversions are counted at all. Shorten it and some leads become unattributed; lengthen it and a click from a week ago claims credit for a lead that a newer click really produced.
Two rules that prevent most of the confusion:
- Use the same window everywhere you compare numbers. A 7-day window on one side and a 1-day window on the other produce a gap that is an artefact of configuration, not a finding.
- Match the window to your consideration time. If 80% of your leads arrive within three days, a 7-day window is generous. If they take three weeks, no click-based window will capture them, and the answer is lead routing rather than a longer window.
The overlap problem
With a 7-day window, a user who clicks ad A on Monday and ad B on Wednesday, then converts on Thursday, is credited to both systems differently. First-party tracking typically credits the last click; the platform may credit the first, or split the credit. This is a real source of disagreement between the two CPLs — see real CPL vs platform CPL.