BOGO margin worked example for buy one get one free

Last updated: 2026-07-31

Written and reviewed by Seller Profit Guard Editorial Team.

A synthetic buy-one-get-one-free offer uses USD 30 regular price, 100 placed orders, 90% retained outcomes, USD 9 unit cost, and a 10% contribution target. Contribution is USD 284; covering 100 placed-order rewards uses 83.33% of 120 available units, within the entered 90% threshold.

buy-one-get-one-free worksheet separating paid units, reward units, collected revenue, fulfilled cost, target headroom, and decision — This original diagram explains a traceable two-unit free-reward decision with synthetic aggregates.

Freeze the 1 + 1 free mechanic

The customer pays for one unit and receives one additional unit at a 100% reward discount. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

Both units must be added under the supported checkout rule. Topic 1 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

Derive 90 retained orders

Multiply 100 placed orders by the 90% mature retained rate. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

The planning result does not predict a specific retained order. Topic 2 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

Collect USD 2,700 merchandise

Each retained order collects USD 30 because only the paid unit carries merchandise revenue. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

Buyer shipping is zero in this fixture. Topic 3 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

Cost 180 fulfilled units

Multiply 90 retained orders by two units and USD 9 product cost. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

The free reward consumes USD 810 of product cost. Topic 4 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

buy-one-get-one-free worksheet: cost 180 fulfilled units — This original diagram makes a traceable two-unit free-reward decision reviewable.

Add order-level costs and fees

Apply USD 5 combined packaging, fulfillment, and shipping, 8% percentage fees, and USD 0.30 per placed order. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

Keep each basis visible. Topic 5 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

Subtract loss and setup

Apply USD 0.50 adverse loss per placed order and USD 50 promotion setup. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

Do not hide them inside product cost. Topic 6 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

Read USD 284 contribution

Compare 10.52% contribution margin with the 10% target reserve. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

USD 14 headroom is narrow and belongs only to this fixture. Topic 7 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

Check 83.33% reward inventory utilization

Cover all 100 placed orders with one reward unit, then divide 100 by 120 available units. In the buy-one-get-one-free worksheet, record the value, unit, denominator, source version, evidence date, maturity state, owner, reviewer, and uncertainty. Recalculate from a clean aggregate or synthetic packet before formatting any rate, amount, boundary, or decision.

The remaining twenty-unit headroom is a conservative operational reserve; it does not reserve inventory or forecast redemptions. Topic 8 keeps one supported case, one defective case, the correction step, and the reason the conclusion belongs to a traceable two-unit free-reward decision rather than a platform promise, demand forecast, or universal promotion rule.

Quantity and denominator control: bogo margin example: buy one get one free

Reconcile paid units, reward units, placed orders, retained orders, and fulfilled units before calculating. Control 1 names the authority, owner, review frequency, exception code, threshold, expiry, correction trigger, and prior restorable offer packet.

Every rate and cost must name its denominator. Apply the control specifically to a traceable two-unit free-reward decision; distinguish official platform behavior, seller configuration, seller records, calculator formulas, estimates, and scenario assumptions.

Release and restoration control: bogo margin example: buy one get one free

Require calculation, content, similarity, SEO, image, browser, mobile, privacy, live, and rollback evidence. Control 2 names the authority, owner, review frequency, exception code, threshold, expiry, correction trigger, and prior restorable offer packet.

Restore on formula, route, source, privacy, accessibility, or health regression. Apply the control specifically to a traceable two-unit free-reward decision; distinguish official platform behavior, seller configuration, seller records, calculator formulas, estimates, and scenario assumptions.

buy-one-get-one-free worksheet: release and restoration control: bogo margin example: buy one get one free — This original diagram makes a traceable two-unit free-reward decision reviewable.

Cost and outcome maturity control: bogo margin example: buy one get one free

Close product, fulfillment, parcel, fee, refund, return, dispute, and recovery windows. Control 3 names the authority, owner, review frequency, exception code, threshold, expiry, correction trigger, and prior restorable offer packet.

Provisional evidence stays visibly provisional. Apply the control specifically to a traceable two-unit free-reward decision; distinguish official platform behavior, seller configuration, seller records, calculator formulas, estimates, and scenario assumptions.

Reward-inventory control: bogo margin example: buy one get one free

Keep required reward units, available units, committed units, reserve floor, maximum utilization, replenishment, and fulfillment capacity visible. Control 4 names the authority, owner, review frequency, exception code, threshold, expiry, correction trigger, and prior restorable offer packet.

A scenario result never reserves inventory. Apply the control specifically to a traceable two-unit free-reward decision; distinguish official platform behavior, seller configuration, seller records, calculator formulas, estimates, and scenario assumptions.

Privacy and access control: bogo margin example: buy one get one free

Use aggregates, synthetic fixtures, redacted pointers, access limits, retention rules, and deletion rules. Control 5 names the authority, owner, review frequency, exception code, threshold, expiry, correction trigger, and prior restorable offer packet.

Exclude buyer, order, payment, coupon, credential, token, and OAuth data. Apply the control specifically to a traceable two-unit free-reward decision; distinguish official platform behavior, seller configuration, seller records, calculator formulas, estimates, and scenario assumptions.

Freeze the 1 + 1 free mechanic: BOGO scenario drill

Recreate “Freeze the 1 + 1 free mechanic” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. The customer pays for one unit and receives one additional unit at a 100% reward discount. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

Both units must be added under the supported checkout rule. Drill 1 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

Derive 90 retained orders: BOGO scenario drill

Recreate “Derive 90 retained orders” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. Multiply 100 placed orders by the 90% mature retained rate. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

The planning result does not predict a specific retained order. Drill 2 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

Collect USD 2,700 merchandise: BOGO scenario drill

Recreate “Collect USD 2,700 merchandise” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. Each retained order collects USD 30 because only the paid unit carries merchandise revenue. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

Buyer shipping is zero in this fixture. Drill 3 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

buy-one-get-one-free worksheet: collect usd 2,700 merchandise: bogo scenario drill — This original diagram makes a traceable two-unit free-reward decision reviewable.

Cost 180 fulfilled units: BOGO scenario drill

Recreate “Cost 180 fulfilled units” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. Multiply 90 retained orders by two units and USD 9 product cost. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

The free reward consumes USD 810 of product cost. Drill 4 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

Add order-level costs and fees: BOGO scenario drill

Recreate “Add order-level costs and fees” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. Apply USD 5 combined packaging, fulfillment, and shipping, 8% percentage fees, and USD 0.30 per placed order. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

Keep each basis visible. Drill 5 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

Subtract loss and setup: BOGO scenario drill

Recreate “Subtract loss and setup” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. Apply USD 0.50 adverse loss per placed order and USD 50 promotion setup. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

Do not hide them inside product cost. Drill 6 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

Read USD 284 contribution: BOGO scenario drill

Recreate “Read USD 284 contribution” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. Compare 10.52% contribution margin with the 10% target reserve. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

USD 14 headroom is narrow and belongs only to this fixture. Drill 7 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

Check 83.33% reward inventory utilization: BOGO scenario drill

Recreate “Check 83.33% reward inventory utilization” from the synthetic 1 + 1 free and 2 + 1 half-off fixtures. Cover all 100 placed orders with one reward unit, then divide 100 by 120 available units. Change one supported input, preserve the original packet, show the collected-revenue and fulfilled-cost bridge, and attach the expected Block, Review, or Ready state to the buy-one-get-one-free worksheet.

The remaining twenty-unit headroom is a conservative operational reserve; it does not reserve inventory or forecast redemptions. Drill 8 includes a supported offer, below-target case, invalid case, corrected case, product-cost change, parcel-cost change, and reward-discount change. Explain what moved, what remained fixed, which threshold changed, and what evidence permits the next step.

What a traceable two-unit free-reward decision can and cannot prove

It can prove that entered aggregate assumptions follow the declared dated offer mechanics, distinct paid and reward quantities, order grain, regular-price basis, retained outcomes, fulfilled costs, fee bases, adverse loss, setup cost, reward inventory, thresholds, confirmations, formula version, and evidence scope.

It cannot prove platform eligibility, checkout behavior, lawful price display, live inventory reservation, demand, redemption, conversion, product mix, buyer behavior, incrementality, accounting profit, liquidity, tax treatment, or future campaign results.

Block, review, release, and restore the buy-one-get-one-free worksheet

Block non-finite numbers, duplicate scenarios, invalid dates, missing confirmations, private exposure, missing mechanics, incompatible periods, stale scope, or declared conflicts. Review a valid scenario below target or above its reward-inventory threshold. Ready means both structures preserve the declared contribution and inventory controls.

Release only a reversible public model with synthetic defaults, first-party sources, original diagrams, accessible labels, self-canonical, Article and Breadcrumb schema, contextual links, strict 404 behavior, correction policy, and rollback evidence.

Sources and further reading

Seller Profit Guard methodology: Evidence versions, formulas, privacy, correction, release, and rollback.
Seller Profit Guard data privacy: Local-first boundaries for buyer, order, promotion, payment, credential, and raw-record data.
Shopify Help: Buy X get Y discounts: Official qualifying quantity, reward quantity, discounted value, cart-addition, inventory, channel, uses, combination, and timing rules. Reviewed July 31, 2026.
Shopify Help: Combining discounts: Official application order, best-discount selection, plan-specific same-item rules, and Buy X Get Y combination limits. Reviewed July 31, 2026.
Etsy Help: Set up sales and discounts: Official sales, promo-code, discounted-bundle, highest-discount, and non-stacking context. Reviewed July 31, 2026.
FTC: Unfair or Deceptive Fees FAQ: United States guidance says a BOGO-adjusted total price follows only after the transaction meets promotion requirements. Reviewed July 31, 2026.

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Next step: Open Seller Profit Guard.

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