Definition
Attribution is the method used to assign credit for conversions to channels, campaigns, and touchpoints.
Example
In last-click attribution, 100% of credit goes to the final touchpoint. In multi-touch attribution, credit is split across touchpoints.
How to use it
- Define attribution consistently before comparing ROAS/CPA across channels.
- Use incrementality tests when possible to estimate true lift.
Common mistakes
- Treating attribution as causal truth (it's model-based credit).
- Comparing channels with different windows and tracking coverage as if the numbers are comparable.
Measured as
Measure Attribution with a fixed attribution window, conversion event, and spend basis before comparing campaigns or creative tests.
Misused when
- Treating attribution as causal truth (it's model-based credit).
- Comparing channels with different windows and tracking coverage as if the numbers are comparable.
Operator takeaway
- Define attribution consistently before comparing ROAS/CPA across channels.
- Use incrementality tests when possible to estimate true lift.
- Use Attribution only inside a stable attribution rule, conversion definition, and time window so campaign comparisons stay honest.
- If performance changes, check whether the metric moved for a real business reason or because the measurement setup changed underneath you.
Next decision
- Read Attribution vs incrementality: what to trust, when, and how to test if the decision depends on interpretation, policy, or trade-offs beyond the raw formula.
- Decide which report owns Attribution before comparing campaigns, channels, or creative tests.
Where to use this on MetricKit
Guides
- 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.
- UTM + GA4 attribution: practical tracking for paid ads (without lying to yourself): A practical guide to UTMs and GA4: consistent source/medium/campaign tagging, conversion deduplication, and common attribution traps.