Use a benchmark you can explain
Choose a marketing comparison that has the same units and context.
Start with a comparable baseline
Match period, audience, channel, and outcome definition. A lead form rate can be higher than a purchase rate simply because the actions require different commitments. An industry average is secondary to a clean internal comparison when you can construct one.
Create a baseline range
Use several comparable periods and show the observed range with counts. If holiday weeks are systematically different, group them separately. A single exceptional week should not set the standard for every later campaign.
Decide what would justify intervention
Choose a change large enough to matter and check tracking and traffic mix first. If a campaign is inside normal variation, wait for more evidence unless another guardrail indicates a problem. Keep the comparison definition in the scorecard.
Try a related tool
Find the share of eligible visits that completed a defined action. Count at most one conversion per visit for this calculation.
