The Amazon P&L explained: where the money actually goes

Amazon economics confuse people because the costs arrive in different places: some deducted per order, some invoiced monthly, some buried in promotions and some disguised as advertising necessity. Lay them out as one waterfall from retail price to contribution margin and the channel stops being mysterious and starts being manageable.

The waterfall, top to bottom

• Referral fee: Amazon’s commission per sale, a percentage of the sale price that varies by category. The entry ticket; nothing to optimise except category correctness.
• Fulfilment fee (FBA): a per-unit charge driven by size and weight bands. Small dimensional changes move bands: pack engineering is P&L work.
• Storage: monthly per-cubic-foot charges that rise steeply in Q4, plus surcharges for stock that sits too long. Slow inventory literally rents against you.
• Promotions and subscriptions: funded discounts, coupons and the Subscribe & Save discount all come off your line, deliberately, one hopes.
• Advertising: technically discretionary, practically structural in competitive categories. Allocate it per ASIN when judging product economics.
• Returns and disposals: return processing, unsellable stock and removal fees; healthcare return rates are low but disposals of dated stock are not.

Vendor P&Ls hide differently

Selling wholesale to Amazon replaces visible fees with negotiated terms and quiet deductions: trade terms, damage allowances, chargebacks and shortage claims arrive on remittances rather than fee reports. The waterfall exercise matters even more there, because nobody sends you a tidy per-unit fee statement. Our Vendor vs Seller framework covers the comparison properly.

Build the per-unit view

For each hero product, one row: retail price, then every waterfall line as money, not percentages, down to contribution per unit. Percentages hide the truth on low-priced items, where a fixed fulfilment fee can quietly consume the economics of a small pack. This row is where pack architecture decisions come from: multipacks and larger formats often exist precisely to carry fixed fees better.

The decisions the P&L should drive

• Which pack sizes are viable on Amazon at all, and which belong to other channels.
• Where price changes are absorbed by fees versus flowing to margin.
• Which products can fund advertising and promotion, and which must ride organically.
• When Q4 storage economics say ship later, or lighter.
• Whether a struggling ASIN has a margin problem or a velocity problem: the fixes differ.

Keep it honest over time

Fees change, packs change, ad costs drift. Rebuild the waterfall quarterly and after any fee announcement, and reconcile it against actual settlement data rather than rate cards: the difference between theoretical and actual fees is itself a finding, usually about dimensions, damage or misclassification.

Go deeper

• Measuring true profitability per ASIN
• What is the IPI score, and why does it cap your storage?
• ACoS and TACoS: which number actually matters?