Formula
Sale Price = Price × (1 − Discount) · Extra volume needed = Profit Before ÷ Profit After
FAQ
Why do small discounts need so much extra volume?
Because discounts cut profit per unit directly. A 20% discount on a product with a 40% margin halves the per-unit profit — you need double the volume just to stay level.
Are there better alternatives to discounting?
Bundles, free shipping thresholds and gifts-with-purchase protect the list price while still creating a promotion.