= orders ÷ impressions for the feature.

Example: 100 buyers saw your post-purchase offer, 12 accepted → 12% conversion. For post-purchase, 5–15% is typical.

= (AOV with feature − AOV without) ÷ AOV without.

Compare cohorts in the same period. Don't compare last month (no FBT) to this month (FBT enabled) without controlling for seasonality.

The line item value of items added by the feature, not the total order value.

Example: Customer's order is $80 total. The cart upsell added a $15 item. Revenue attributed to the upsell = $15, not $80.

Don't confuse "revenue attributed" with "orders saved" or "AOV grown". Each metric answers a different question.

Look at revenue attributed per impression. It's the simplest single number for "is this feature paying for itself."