Method and definitions
Actual revenue or forecast leads × close rate × deal value; contribution = revenue × gross margin − campaign investment; contribution ROI = contribution ÷ campaign investment × 100.
Use attributed revenue and campaign costs consistently. Forecast leads must be from a mature, comparable cohort. This is contribution-based marketing ROI, not net business profit or causal incrementality. Forecast mode is an estimate. Include agency and creative in total campaign investment without counting them twice.