ROMI is a measurement of the effectiveness of a marketing campaign.
It takes a baseline level of business activity and measures it against the business activity from a time when a marketing campaign is running.
The final return is the extra profit above regular business activity less the cost of running the marketing campaign.
Baseline Profit = Baseline revenue – Baseline Cost of Goods Sold
Marketing Campaign Profit = Revenue – Cost of Goods Sold
Profit with Marketing Campaign Cost = Profit – Marketing Cost
Campaign Uplift = Profit with Marketing Cost – Baseline Profit
Return on Marketing Investment = (Campaign Uplift / Markting Cost) x 100%