A generous-sounding coupon can quietly sell inventory at a loss. Margin protection puts a hard floor under every promotion: you decide the minimum gross margin you’ll accept, and the system trims or rejects any discount that would cut below it — automatically, per line item, at checkout.
How gross margin is measured
gross margin = (selling price - cost price) / selling price
A $100 item that costs you $60 carries a 40% gross margin. A 30% off code would sell it at $70 — a 14.3% margin. With a 25% floor, that discount gets trimmed (or the code rejected, your choice).
⚠️ Warning: The floor can only protect products that have a cost price. Items without one are discounted normally — the system can’t defend a margin it can’t calculate. The Promotions page tells you exactly how many active products are uncovered.
🖼️ [SCREENSHOT: Cost-coverage note showing partial coverage in amber — Marketing → Promotions, guardrails card]
The dealer-wide floor
On Marketing → Promotions, the Promotion guardrails card sets policy for your whole store:
| Field | What it does |
|---|---|
| Minimum margin floor (%) | No promotion may leave a line below this gross margin. Blank = no floor |
| When a promo would breach it | Trim the discount to the floor — the shopper still gets a (smaller) discount, priced exactly at your floor. Reject the code entirely — the code errors instead of applying |
Click Save guardrails — changes apply to every future checkout immediately.
💡 Tip: Trim is the customer-friendly default: the order still goes through at the best price you’re willing to offer. Reserve Reject for codes that must never partially apply.
Per-promotion overrides
Each promotion’s form has a Margin protection section that inherits the dealer-wide policy unless you override it:
| Field | What it does |
|---|---|
| Margin floor override (%) | Blank inherits the dealer default. Set a number to give this one promotion a stricter (or looser) floor |
| If it would breach the floor | Use dealer default · Trim the discount to the floor · Reject the code entirely |
Use an override when one campaign plays by different rules — a clearance event allowed to run thinner, or a brand promo that must never trim below MAP economics.
Worked example
Dealer floor: 25%, Trim. Code: BIG30 — 30% off, whole order.
| Item | Price | Cost | 30% off would leave | Result |
|---|---|---|---|---|
| Trimmer | $200 | $90 | $140 sale price — 35.7% margin | Full discount applies: $60 off |
| Chainsaw | $400 | $240 | $280 sale price — 14.3% margin | Trimmed to the floor: $80 off instead of $120, selling at $320 (exactly 25% margin) |
| Blower | $150 | (none) | can’t be calculated | Full discount applies — uncovered |
The shopper sees one combined discount; each line contributed only what your floor allows. With Reject instead of Trim, the chainsaw’s breach would have refused the code outright.
Never-discount products
For items that must never be discounted at all — MAP-sensitive lines, loss leaders already at floor — open the product and check Exclude from promotions. That beats every promotion and popup reward, regardless of floors. The guardrails card shows a count of flagged products.
🖼️ [SCREENSHOT: Product page “Exclude from promotions” checkbox — Catalog → Products → (product), next to Featured Product]
Getting to 100% coverage
- Check the coverage note on the Promotions page — it counts active products with no cost price.
- Fill cost prices in the catalog (Products) or via Bulk Import; vendor feeds can supply them automatically (Product Feeds).
- When the note turns green, every discounted line is margin-checked.
Next: Signup popup.