Most founders look at Seller Central’s Business Reports and freeze. Eighty-four columns of numbers, half of them in the same units, and nothing tells you what’s actually leaking. So they default to staring at gross revenue, watch ACOS, and call it a quarter.
Here’s the short version of what a real operator scans for — six lines you can pull in 90 seconds, and the math behind each one.
What is the first thing to look at on an Amazon P&L?
Pull the Sales Dashboard and subtract returns from the same period. If you cannot do that in one click, your reporting is set up wrong.
How do I check whether Amazon fees are eating into margin?
A 1.5% drift in your fee ratio on a $2M brand is $30,000 you didn’t budget for. Most aggregator dashboards lag the actual fee schedule by 30+ days, which means the drift is invisible until quarter-end. See aggregator software accuracy for why.
How do I find storage waste per SKU?
The pattern we see most often: a brand has 15–25% of SKUs each contributing less than 1% of revenue, but together those SKUs eat 6–9% of total margin via storage tax. Plug that leak first.
What is the difference between ACOS and incremental return?
The fastest test: cut spend on one ASIN for two weeks and measure the total revenue drop. If revenue is flat, the ads were not earning anything. We unpack this in detail in why ACOS is a vanity metric.
What does a healthy refund + safe-T claim ratio look like?
Watch this weekly. A 14-day spike on a hero SKU can torch ranking in a window that takes 60 days to recover.
How do I calculate contribution margin per unit?
This is the only number that tells you whether to scale, hold, or kill. Every other metric on the dashboard is a proxy.
Once you can scan a P&L this way, the next question is which leak is biggest in dollars and which to plug first. That is what The Profit-Leak Method ranks for every brand we audit.
The questions readers actually ask after this article.
What is the most important number on an Amazon P&L?
Contribution margin per unit — the dollars left after Amazon fees, FBA fees, returns, storage, and ad spend. Gross revenue and ACOS tell you nothing about whether the business is profitable; contribution margin tells you whether each unit sold is making or losing money.
Where do I find Amazon fees broken out in Seller Central?
Reports → Payments → Transaction view shows every fee line item per order. For aggregate views, the Fee Preview report (Reports → Fulfillment by Amazon) lists referral, FBA fulfillment, and storage fees by ASIN. Reconcile these monthly against your dashboard's reported fees — drift of more than 1% means your aggregator is using a stale fee table.
How often should I review my Amazon P&L?
Top-line revenue and fee creep should be reviewed weekly. Return ratio, ad spend versus incremental revenue, and contribution margin per unit should be reviewed every two weeks. Long-term storage fees and aged-inventory surcharges should be reconciled monthly. Quarterly is too late — by then a leaking SKU has cost you 90 days of margin.
What is a healthy Amazon contribution margin?
For most consumer-product brands, a healthy contribution margin sits at 22–35% of net revenue after all variable costs. Below 18% means the SKU is fragile to any fee increase or competitive price pressure. Above 35% usually means there is room to spend more aggressively on ads to capture share.
What is the difference between ACOS and TACoS, and which should I use?
ACOS measures spend against ad-attributed revenue (a 7-day attribution window). TACoS measures spend against total revenue, including organic sales. ACOS feels good at 12% but is meaningless if your TACoS is 28% — you are still spending nearly a third of every dollar on ads. Track both; manage to TACoS.
