A store with healthy unit economics and a bad month has a volume problem, which more sales fix. A store with weak unit economics and a good month has a structural problem, which more sales make worse. The two look identical on a revenue chart and require opposite responses.
The walk is short: net price, minus goods, minus the parcel and the payment fee, minus the advertising the order needed. What survives is what the order contributed towards rent, salaries and profit, and the arithmetic works on a single product as readily as on a whole store. The SKU margin sheet runs it for every product in one file.
It is also the honest test for a price change, a new channel or a discount: each of them changes the unit before it changes the total, and the total is where the change becomes visible far too late. Margin-based pricing runs the same walk backwards, from the margin a product must keep to the price it needs.
