Definition
First-click attribution assigns 100% of the conversion credit to the first known touchpoint in the path.
Example
A prospect clicks a blog ad and later converts via email; first-click assigns full credit to the blog ad.
How to use it
- Useful for evaluating acquisition channels, but it can under-credit closers.
- Keep lookback windows consistent; first-click is sensitive to window length.
- Use it to inform top-of-funnel investment, not final ROI decisions.
Common mistakes
- Using first-click to judge retargeting performance.
- Comparing first-click results to last-click without context.
Measured as
Measure First-click Attribution with a fixed attribution window, conversion event, and spend basis before comparing campaigns or creative tests.
Misused when
- Using first-click to judge retargeting performance.
- Comparing first-click results to last-click without context.
Operator takeaway
- Useful for evaluating acquisition channels, but it can under-credit closers.
- Keep lookback windows consistent; first-click is sensitive to window length.
- Use it to inform top-of-funnel investment, not final ROI decisions.
- Use First-click 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 First-click 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.