return on marketing investment (ROMI)
Also called: ROMI, marketing ROI
Incremental margin from a marketing activity minus its cost, divided by its cost. Computed on revenue instead of margin, or on all growth instead of growth above the baseline, it flatters every campaign.
Return on marketing investment (ROMI) answers whether a marketing activity paid for itself and by how much: ROMI = (incremental margin − cost) ÷ cost × 100%. A ROMI of 30% means that for every hryvnia spent, the activity brought the hryvnia back plus 30 kopecks of contribution margin above what would have happened anyway. A negative ROMI means it did not cover its cost.
Both parts of the numerator matter. Incremental means only results above the baseline count; margin means contribution margin, not revenue. Swap either one and ROMI flatters every campaign: revenue ÷ spend counts the costs that leave with each sale as a return, and growth without a baseline credits marketing with referrals, seasonality and the market. The same campaign can show 30%, 70% or 270% depending on which shortcut is taken.
ROMI is most useful for comparing channels with one method and one yardstick, so budget moves toward what actually adds margin. Treat it with the humility small numbers deserve: with three to six opportunities per channel, one deal changes the picture, and in B2B many results land months after the spend. Report the assumptions (baseline, value per opportunity, time window) next to the percentage.
Example
Klasna for Teams' autumn 2026 campaign cost 325,000 UAH and brought 13 opportunities above the baseline. With one opportunity worth 32,544 UAH of expected contribution (a planning assumption: 1 in 5 won × 480 lessons in year one × 339 UAH):
- Incremental margin: 13 × 32,544 = 423,072 UAH.
- After cost: 423,072 − 325,000 = 98,072 UAH.
- ROMI = 98,072 ÷ 325,000 = 30.18%.
The shortcuts: without the control, 17 extra opportunities give 553,248 − 325,000 = 228,248, a ROMI of 70.23%; crediting all 37 opportunities gives 1,204,128 − 325,000 = 879,128, a ROMI of 270.5%.
Events brought the most leads (60) and the worst ROMI. The channel numbers are small, so the honest reading is "shift some budget and measure again with a control chosen in advance", not "events never work".
Common mistakes
- Revenue ÷ spend. That ratio counts the costs of delivering every sale as return; use contribution margin.
- No baseline. Growth that would have happened anyway inflates ROMI the most; subtract a baseline from a control or trend.
- Different yardsticks per channel. Compare channels only with the same value per opportunity and the same time window.
- Reading small numbers as verdicts. With a handful of opportunities per channel, one deal flips the sign; decide in steps and re-measure.
- Measuring before deals close. B2B campaigns pay back over months; a ROMI taken too early understates slow channels.
Learn it in the course
- Measuring marketing with a baseline · Why "the webinars returned twelve times their cost" is wrong: a baseline from the same months last year and a control group, incremental margin instead of revenue, and an honest ROMI.
- Case: a quarter's budget and what really moved · Leads more than doubled this autumn. Split the credit between marketing and the baseline, channel by channel, and recommend where next quarter's 325,000 UAH should go.