What is Attribution window?
An attribution window is the period after someone clicks or views an ad during which a resulting purchase will still be credited to that ad by the advertising platform.
Updated
An attribution window is a reporting setting, not a fact about the world. Widen it and your ROAS improves without anything changing in the business; narrow it and the same Meta ads campaigns look worse. This is the most common reason two people looking at the same account disagree about how it is performing.
For a considered purchase — occasion wear, furniture, anything above a few thousand rupees — a 7-day click window usually reflects reality, because people genuinely do leave and come back. For an impulse product a 1-day window is closer to the truth, and a long view-through window on such a product mostly credits ads for sales that would have happened anyway.
The practical rules are simple. Pick a window, write it down, and hold it constant so month-on-month comparisons mean something. Note it on any report you send or receive. And when the platform figure and the bank account disagree, trust blended ROAS or MER, because those do not depend on a setting anyone can change.
A worked example
The same week of sales is read on two settings: a 7-day click window and a 1-day click window.
- 7-day click: ₹4,20,000 attributed on ₹70,000 spend = 6.0x
- 1-day click: ₹2,80,000 attributed on ₹70,000 spend = 4.0x
- Nothing about the business changed — only the window did
Same week, same spend, two very different ROAS figures.
Common mistakes
- Comparing this month's ROAS to last year's when the attribution setting changed in between.
- Using a long view-through window on a low-consideration product, which credits the ads for sales they barely touched.
- Assuming a longer window is more accurate. It is more generous, which is not the same thing.
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