Why a 15% discount can remove more than 15% of profit

“Fifteen percent off” sounds like a fifteen-percent decision. It is not. The discount applies to revenue, while the cost of delivering the same scope can stay almost unchanged.

Start with price, cost, and gross profit

Consider an illustrative job quoted at $260 with an estimated total cost of $167. Before any discount, the modeled gross profit is $93. That is the amount left after estimated job costs in this simplified example—not the owner’s take-home pay and not net profit.

Apply the discount to price—not cost

A 15% discount takes the selling price to $221. If the same team still performs the same scope with the same estimated costs, modeled gross profit becomes $54.

The price fell 15%, but modeled gross profit fell by roughly 42% in this example. The point is not that a 15% discount is always wrong. The point is that its effect cannot be understood by looking at the percentage on the coupon alone.

Change the offer before copying the work

When a client needs a lower price, consider whether the offer itself can change:

• Reduce or separate optional tasks.
• Change frequency only when it genuinely changes the expected condition or workflow.
• Offer add-ons separately instead of including everything in one price.
• Use a documented introductory offer only when the acquisition cost is intentional.

Do not quietly remove promised scope or assume recurring work will always be faster. Model the revised version, explain it clearly, and confirm what the client is approving.

All numbers are illustrative. TidyMargin is an educational planning aid, not accounting, legal, tax, or pricing advice. Validate your costs and local market.