The ground rules every Amazon promotion should follow.

Picture a scene we've watched a dozen times. A brand has a hero ASIN doing solid numbers, organic rank is stable on the main keyword, the Buy Box is locked. The team wants more — Q4 is coming, the inventory is on the water, and someone in the Tuesday meeting suggests "let's run a Lightning Deal." The deal gets scheduled at a 20% discount, everyone moves on to the next agenda item. Two weeks later the deal goes live for six hours on a Thursday afternoon, sells through 70% of the inventory in the first hour at near-zero contribution margin, Amazon cancels the deal because stock dipped below its threshold, and the listing loses the Buy Box for the rest of the afternoon while the system reconciles. By Friday the ASIN has dropped three positions on the main keyword and conversion rate on the regular price has dipped because the listing now shows a "was" price that anchors shoppers to a lower expectation.

That deal didn't go badly because someone picked the wrong mechanic. It went badly because nobody walked through the ground rules before clicking submit.

Amazon offers a long menu of promotional mechanics — coupons, Lightning Deals, Prime Exclusive Discounts, Subscribe & Save, sale prices, the Outlet, BOGO. The mechanic you pick matters, but it matters less than the rules of the game underneath. This article walks through the six rules we apply to every promo we launch — for ourselves and for the brands we work with. Treat them as a pre-flight checklist for any promotion, of any type, in Seller or Vendor Central.

Rule 1 — Anchor the discount to a genuine reference price

Almost every Amazon promotion is calculated against a reference price: the "Was" price, the List Price, or the historical Featured Offer price over the last 30 days. That reference is what shoppers see crossed out next to your promo price, and it's what Amazon uses to decide whether your deal qualifies as a deal at all.

The problem is that the reference price isn't something you set once and forget. Amazon recalculates it every day. If you've been selling at €19.90 for the last six weeks and you submit a Lightning Deal at €17.90, Amazon may decide the "real" price is €19.90, the savings are about 10%, and the deal isn't worth promoting. The deal page badge that you were counting on to drive traffic never appears, and you've effectively given a 10% discount to your existing shoppers for nothing.

The fix isn't a hack. It's a habit:

• Set the List Price at a level you genuinely defend at full margin. This is your aspirational shelf price.
• Use Was Price to reflect the last price you actually sold significant volume at — not yesterday's pricing experiment.
• If you're planning a deep discount (a Lightning Deal, a Prime Exclusive Discount during Prime Day), let the regular price sit at your defensible level for at least three to four weeks beforehand. Amazon's 30-day window will catch up.
• If you've been running a long-term low price, accept that you'll need a "reset period" at the higher price before a meaningful deal can run. There is no shortcut.

Rule 2 — Re-check eligibility 24–48 hours before go-live

Most operators check promo eligibility when they submit the promotion. Amazon checks it again the day the promo runs. An ASIN that passed every gate two weeks ago can fail today, and you'll only find out when the deal silently doesn't appear.

The eligibility surfaces that move most often:

• Buy Box ownership. A third-party offer can undercut you between submission and launch. If you don't own the Buy Box on the deal day, the deal won't run.
• Star rating. Most deal types require ≥ 3.5 stars with a minimum review count. A few one-star reviews in the wrong week can knock a hero ASIN out of eligibility.
• Inventory. Lightning Deals and 7-Day Deals require specific minimum stock levels relative to expected deal velocity. A late FBA inbound or an unplanned spike can push you below the floor.
• Listing and policy warnings. A new suppression — image violations, restricted keywords in the title, a category compliance flag — disqualifies the ASIN instantly.

Build a recurring 48-hour check into your promo workflow. The cost of doing it is five minutes; the cost of skipping it is a silently cancelled deal, often during the only week of the quarter where you actually needed it to run.

Rule 3 — Clear the contribution margin floor before launching

Most promo failures aren't operational — they're maths. Before scheduling any discount, sit down and write out the unit economics at the promo price, end to end. Most teams skip this because the calculation feels obvious; in practice the gap between "obvious" and "documented" is where margin dies.

A useful structure:

• Landed unit cost. Goods, inbound freight, import duties, per-unit warehouse handling, prep fees, labelling.
• Amazon variable fees. Referral fee, FBA fulfilment fee at the deal price, dimensional weight surcharges if you're near a tier boundary.
• Variable overheads. Long-term storage, return rate reserve (use your real category return rate, not the average you wish you had), restocking and reverse logistics costs.
• Marketing cost allocated to the unit. If you're running PPC alongside the promo, the incremental ad spend per unit sold belongs in this column. Promotions are the conversion engine for those ads, not an alternative to them.

What's left after subtracting all of that from the deal price is your contribution margin at the promo price. If that number is negative, you have three legitimate options:

• Don't run the promo. Always available, often correct.
• Run it as a calculated loss with a written ranking hypothesis: how much organic rank you expect to gain, how long you expect to hold it, and what the lifetime value of that rank is. If you can defend the number, the loss is an investment.
• Restructure the offer. A 15% coupon plus a 5% Subscribe & Save can produce the same shopper-facing discount as a 20% Lightning Deal at a meaningfully better effective cost, because not every shopper takes both.

Rule 4 — Stack promos deliberately, never accidentally

Amazon's promo engine will happily let you run a coupon, a Subscribe & Save discount, a Prime Exclusive Discount and a sale price on the same ASIN on the same day. Some combinations compound nicely. Most don't — and the ones that don't are how brands give away 40% of revenue to customers who would have paid full price.

The two failure modes we see most often:

Coupons stacking on Prime Day deals. A permanent 10% coupon left running because nobody removed it stacks on top of a Prime Exclusive Discount during Prime Day. The combined offer is closer to 35% off, the discount budget blows out, and the post-Prime Day reference price collapses because the recent average selling price is now well below the regular price.

Subscribe & Save underneath a Lightning Deal.On the right ASIN — a consumable with high repeat purchase — this stacks beautifully and acquires high-LTV subscribers at the deal price. On the wrong ASIN — a one-off purchase, a gift item, a tool — it just gives away an extra 5% to shoppers who will never subscribe again.

The rule we apply: one headline mechanic at a time per ASIN, plus at most one evergreen low-depth offer (Subscribe & Save or a permanent 5% coupon) on ASINs where the underlying mechanic actually fits. Anything else, you remove for the duration of the headline deal.

Rule 5 — Treat inventory cover as part of the promo, not separate from it

A deal that sells out in the first hour doesn't help you. It doesn't help you commercially — the rest of the deal window is dead. It doesn't help you operationally — Amazon ends the deal early, and depending on the deal type may pause your offer entirely while it reconciles. And it doesn't help you algorithmically — the ASIN loses the Buy Box during reinstatement, organic rank dips, and the post-promo conversion rate on the regular price is suppressed because shoppers who arrived expecting a deal bounce off the listing.

Before scheduling any promotion, estimate the units you'll need with a simple multiplier:

required units = historical conversion rate × expected promo traffic × deal duration

Expected promo traffic depends on the mechanic and the placement: a Lightning Deal on the Deals page during Q4 can see 8–15× normal session volume on the ASIN; a Prime Exclusive Discount with no badge sees a much smaller lift; a coupon that fires only on the search results page is closer to the regular session volume with a higher conversion rate.

Whatever number you land on, refuse to launch unless inbound stock covers at least 120% of the estimate. The 20% buffer is what keeps you in the Buy Box when traffic converts faster than your model predicted — which it usually does on the deal types that matter.

Rule 6 — Decide what success looks like, before launch

Promotions are seductive because the dashboard shows units moved. What it doesn't show is incremental units — sales that wouldn't have happened anyway. A 20% off coupon that produces 500 units of sales where you'd have sold 480 anyway isn't a marketing win, it's a 20% discount on 480 units paid for to acquire 20 extra orders.

Before launch, write down which of these you're actually trying to move — and exactly how you'll read it 14 days later:

• Incremental units versus a 14-day pre-period baseline, adjusted for category seasonality. The simplest honest measure, and almost no one bothers to record the baseline before launching.
• Organic rank movement on the top 3–5 keywords for the ASIN. Tracked daily through the promo window and the 30 days after. Promos that don't move ranking are spending margin to subsidise existing demand.
• New-to-brand customer rate, available to Vendors and Brand-registered Sellers. Useful for measuring whether a promo is acquiring genuinely new shoppers or just discounting repeat buyers.
• Repeat purchase rate over the next 60 days. The metric that turns a Lightning Deal from a one-time revenue event into an LTV instrument — but only if you actually measure it.

Write the metric, the target, and the read-back date in your promo brief before you submit it. The discipline of having to specify "what good looks like" is what stops Amazon promotions from becoming a habit-driven monthly tax on your margin.

The pre-flight checklist

Before you click "Submit" on any Amazon promotion — coupon, Lightning Deal, Prime Exclusive Discount, Subscribe & Save, sale price, BOGO, Outlet — every one of these should be ✓:

1. Reference price is genuine, recent, and defensible.
2. Eligibility re-checked within 48 hours of go-live.
3. Contribution margin at promo price is positive, or the deficit has a written ranking hypothesis attached.
4. Only one headline mechanic active per ASIN.
5. Inbound stock covers ≥ 120% of expected promo-period demand.
6. Success metric, target and read-back date written down before launch.

With those six locked in, the rest of Module 1 becomes mechanical. Each remaining episode covers one specific promotional mechanic — where it appears, who it reaches, how it's priced, and the most common ways operators get it wrong — and you'll apply this same checklist to every one of them.