1. Choose the audience definition
Select a denominator that represents people who could reasonably encounter the offer, then use that same definition for future comparisons.
2. Enter reachable audience
Use unique people rather than impressions. For email, delivered recipients are usually more informative than the full list size.
3. Enter completed buyers
Count completed sales attributable to the same campaign and time window.
4. Check attribution and timing
Do not combine buyers from a longer period with an audience count from a shorter period.
5. Review the percentage and ratios
Use the main rate with buyers per 1,000 and the audience-to-buyer ratio for easier interpretation.