Definition
Attribution window is the time period after an ad interaction during which conversions are credited to that ad.
Example
A 7-day click window credits conversions that happen within 7 days after a click. A 1-day view window credits conversions within 24 hours after an impression.
How to use it
- Keep attribution windows consistent when comparing ROAS/CPA over time.
- Choose windows that match your purchase cycle; short windows can under-credit longer-cycle products.
Common mistakes
- Comparing ROAS across platforms with different default windows.
- Shortening windows and concluding performance dropped when it is just timing.
Why this matters
This term matters because it affects how you interpret performance and make budget decisions. If you use inconsistent definitions or windows, ROAS/CPA can look "better" while profit gets worse.
Practical checklist
- Write a 1-line definition for "Attribution Window" that your team will use consistently.
- Keep the time window consistent (weekly/monthly/quarterly) when comparing trends.
- Segment results (channel/plan/cohort) before drawing big conclusions from blended averages.
- Sanity-check with a related calculator from the same category on MetricKit.
- Read the related guide (e.g., Paid ads funnel: CPM, CTR, CVR -> CPC, CPA, ROAS (with profit)) for context and common pitfalls.
Where to use this on MetricKit
Calculators
- Break-even CVR Calculator: Compute the CVR required to break even (and hit a target) given CPM, CTR, AOV, and contribution margin.
- Click-through Conversion Rate Calculator: Calculate click-through conversion rate (click-to-conversion CVR) and estimate required clicks for target conversions.
- ROAS Calculator: Calculate Return on Ad Spend (ROAS) and estimate contribution profit after ad spend.
- Break-even ROAS Calculator: Estimate the break-even ROAS based on contribution margin assumptions.
- Target ROAS Calculator: Estimate a target ROAS to cover variable costs plus a desired margin buffer.
Guides
- Paid ads funnel: CPM, CTR, CVR -> CPC, CPA, ROAS (with profit): A practical guide to the paid ads funnel: how CPM, CTR, and CVR drive CPC, CPA, ROAS, and profit - with formulas and common pitfalls.
- Incrementality: how to tell if ads are actually driving growth: Platform-reported ROAS can overstate impact. Learn what incrementality means, when it matters, and practical ways to test it.
- MER (blended ROAS): how to use it without fooling yourself: A practical guide to MER: what it is, how it differs from ROAS, how to compute break-even/target MER, and common pitfalls.
- Paid ads measurement hub: ROAS, MER, marginal ROAS, and incrementality: A practical hub for paid ads measurement: connect ROAS to profit, use MER for top-down truth, watch marginal ROAS for scale, and validate incrementality with holdouts.
- Attribution vs incrementality: what to trust, when, and how to test: A practical guide to attribution vs incrementality: common attribution models, window pitfalls, how MER/marginal ROAS fit in, and how to run holdout/geo tests.