Practical learning lesson / 7 MIN READ
Check what the promotion earns after the discount
Redemption can increase while contribution falls, especially when existing customers claim a discount on purchases they would have made anyway.
AI-assisted research and analysis for the SNS Creative Fieldbook
Sources checked 2026-11-05
Compare the whole promotion with a credible no-promotion baseline, including margin, substitution, timing and delivery costs.
What you will leave with: Build a simple contribution model that shows the break-even question and the evidence needed before scaling an offer.
Use this when
- A team is choosing between a discount, bundle or added service.
- A successful redemption report lacks a margin view.
- An acquisition offer may be attracting existing full-price buyers.
This is an illustrative operating model, not accounting, tax or legal advice. Validate cost treatment with finance and promotion claims with relevant local requirements.
Write the world without the promotion
Start with the decision period and the purchases expected without the offer. Identify who would buy anyway, who might switch products and who might genuinely enter the category or return after lapsing. These groups will not usually be known perfectly in advance. Treat them as assumptions to estimate and test. A redemption count alone cannot distinguish additional demand from a subsidy to existing demand.
Choose a baseline consistent with the question. Last week may differ because of seasonality, stock or a payday. A suitable comparison group or well-designed experiment can strengthen the estimate. Keep a separate line for purchases brought forward from a later period: a busy promotional weekend can be followed by a quiet week. The evaluation window should be long enough to see plausible timing effects rather than ending at the most flattering point.
Calculate contribution per fulfilled order
For each promoted product or basket, subtract relevant variable costs from the realized selling price. Include fulfilment, payment fees, packaging, returns, reward cost and extra service where applicable. Use consistent treatment of taxes and shipping. Fixed campaign costs belong in the overall comparison rather than being hidden in an arbitrary per-order number. If a bundle changes the product mix, calculate the bundle’s actual contribution rather than applying an old margin percentage.
The discount changes both the customer’s price and the business’s room to cover costs. An added service may preserve the displayed price but still consume labor or scarce capacity. A gift may have a low purchase cost and an unexpectedly high delivery cost. Compare options using the same scope and observation period. Ask finance which costs vary with the decision and which are already unavoidable.
Include cannibalization and capacity
Cannibalization occurs when the promoted purchase replaces another purchase the business would otherwise have earned. It can happen between products, stores, channels or periods. Estimate lost contribution, not merely displaced revenue. A lower-margin promotional basket may replace a higher-margin regular basket. Existing customers are not automatically bad participants, but their redemptions should not all be counted as newly acquired demand.
Check whether discounted demand displaces full-price demand when capacity is limited. A restaurant with empty weekday tables has a different problem from one fully booked on Saturday. A promotion that overwhelms service can also create cancellations, refunds and damage to future demand. Model the delivery limit before treating additional orders as unlimited upside. Include a pause rule when service quality or stock availability threatens the advertised promise.
Make future value an explicit assumption
A first purchase can be intentionally unprofitable if a well-supported future contribution makes the acquisition worthwhile. But promised lifetime value is not cash already earned. Estimate repeat behavior using appropriate cohorts and account for future discounts, service costs and attrition. Show the result with and without future value so the decision-maker can see how much of the case depends on behavior that has not happened yet.
Whopper Detour links a dramatic introductory offer with app ordering; its award entry reports follow-on behavior and makes claims about cannibalization. Those are entrant-reported results, not a transferable margin model. REI’s store closure provides a contrasting reminder that promotion planning can include declining a selling occasion. Neither case tells a small business which discount it can afford. Start with your economics rather than borrowing the headline.
Set an honest launch and learning decision
Compare total contribution under the offer with the baseline after campaign and operational costs. Run a downside in which more redemptions come from existing buyers and fewer customers return. Decide whether the expected benefit justifies the exposure and whether the learning is worth the cost. If the model only works when every assumption is favorable, reduce scope or redesign the offer before advertising it widely.
Keep price, eligibility, timing and availability claims accurate and easy to understand. The FTC’s US guidance emphasizes truthful, non-deceptive, evidence-based advertising; local promotion and pricing rules need their own review. Close the test with fulfilled orders, contribution, returns and later behavior where available, not just coupon claims. Record which assumptions were wrong so the next offer becomes a better business decision rather than a larger version of the same guess.
Make the reasoning concrete.
Without a promotion, a shop expects 100 units at ₹1,000, with ₹600 variable cost per unit. A promotion reduces price to ₹900 and is expected to sell 130 units. Fixed campaign cost is ₹5,000.
Calculation
Baseline contribution is 100 × (₹1,000 − ₹600) = ₹40,000. Promotional contribution before campaign cost is 130 × (₹900 − ₹600) = ₹39,000. After the ₹5,000 campaign cost it is ₹34,000, which is ₹6,000 below baseline.
Break even
Under these simplified assumptions, promotional units must reach 150 to cover the ₹40,000 baseline plus ₹5,000 campaign cost at ₹300 contribution per unit. This ignores capacity limits, product substitution, later timing effects and future purchases.
Exercise
Recalculate if 20 units would otherwise have sold next month at full price. Then identify what evidence would be needed to justify adding future customer value.
Take the questions into your next brief.
Use these prompts in your own notes. Nothing is submitted from this page.
Baseline
What contribution would likely occur without the offer?
Unit economics
What are realized price and relevant variable costs?
Substitution
Which products, periods or channels might lose contribution?
Capacity
Could the offer displace full-price demand or damage service?
Future value
What repeat behavior is observed and what remains assumed?
Decision rule
What contribution, service and learning conditions justify continuation?
Read with a question in mind.
Burger King
The Whopper Detour →
What must be known beyond the offer’s price?
The app-linked offer invites examination of acquisition, subsequent ordering and cannibalization.
What it does not prove: Entrant-reported commercial results do not supply independently verified margins or prove another deep discount will pay back.
REI Co-op
#OptOutside →
Which selling occasion might a brand deliberately decline?
REI’s closure and paid outdoor time make the opportunity cost of a brand decision visible.
What it does not prove: The case does not isolate the profit effect of closing stores or establish that avoiding a promotion increases sales.
Watch for the wrong conclusion.
- Counting every redemption as an incremental purchase.
- Comparing promotional revenue while ignoring lost contribution.
- Adding lifetime value without a cohort, horizon or cost basis.
- Ending measurement before the post-promotion slowdown can appear.
Your next action
Calculate your proposed offer at three levels of incremental demand, including zero, and identify the assumption that determines whether it breaks even.
Sources & scope
Original editorial synthesis with linked campaign evidence. Exercises and calculations are hypothetical, not historical campaign facts. No named human author or reviewer is claimed.
- The One Show: Whopper Detour, 2019 Creative Effectiveness →Primary award entry · Supports: Objective, execution, distribution, credits, recognition and entrant-reported results.
- The One Show: #OptOutside, 2016 Cross-Platform →Primary award entry · Supports: 2015 store closure, channel mix, partner credits and exact Gold Pencil.
- FTC: Advertising and Marketing Basics →Primary regulator guidance · Supports: US truth-in-advertising principle that claims should be truthful, non-deceptive and evidence-based; specialized products may have additional rules.