A 10% price cut can reduce the contribution from a sale by 40%. That is why a promotion plan should begin with one SKU's economics, not a target revenue figure.
Start with the right metric
Contribution per unit is the amount left after variable costs attributable to that sale. It is not net profit: overhead, tax and later returns need separate treatment.
Record the actual selling price, who funds the discount, commission, unit cost, logistics and advertising per confirmed sale. Do not substitute a remembered average fee for a real charge. A marketplace may fund part of a promotion or apply terms that differ from your baseline.
Worked example: from 10% to 40%
| Per-unit item | Before | Seller-funded 10% discount |
|---|---|---|
| Price | RUB 1,500 | RUB 1,350 |
| Assumed commission, 20% | RUB 300 | RUB 270 |
| Product cost | RUB 650 | RUB 650 |
| Logistics | RUB 150 | RUB 150 |
| Advertising | RUB 100 | RUB 100 |
| Contribution | RUB 300 | RUB 180 |
This assumes a price-based commission and unchanged other unit costs. It is an illustration, not a marketplace tariff. Contribution falls by RUB 120, or 40%. To match the RUB 30,000 contribution from 100 original sales, the promotion needs 167 sales at RUB 180 each: roughly 67% more units.
More volume cannot rescue a zero or negative contribution. If advertising cost or returns increase, the required lift grows further.
Compare three scenarios in CSV or Excel
Create one row per SKU for “baseline”, “seller-funded discount” and “shared funding”. Useful columns are sku, price, seller_discount, commission, cost, logistics, ads_per_sale, contribution, expected_units. Calculate contribution = price - commission - cost - logistics - ads_per_sale, then compare contribution × expected_units. This is an illustrative working sheet, not a claim that the product exports this exact format.
After launch, compare the model with actual charges over a consistent period. Schedule a second check because late adjustments and returns can change the result.
Where ProfitVena fits
ProfitVena connects sales, expenses and product metrics. Product 360 places price, sales, stock and returns in context; Profit Engine helps reconcile revenue with configured costs. The result depends on connected sources, data freshness and current unit costs. Wildberries is the live workflow; verify any other connection for your account before relying on it.
Technical part updated in ProfitVena. ProfitVena is part of the Wicsora ecosystem.
Related guide: how to calculate SKU unit economics. The short TenChat version is in Russian.
