Last-click Attribution

Measured as

Measure Last-click Attribution with a fixed attribution window, conversion event, and spend basis before comparing campaigns or creative tests.

Misused when

• Under-crediting upper-funnel channels that create demand.
• Over-crediting branded search for conversions driven by other channels.

Operator takeaway

• Last-click is simple and often actionable, but it under-credits demand creation.
• Use it for clarity, then validate major budget decisions with incrementality tests.
• Use Last-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 Last-click Attribution before comparing campaigns, channels, or creative tests.