Consulting
Marketplace Seller Unit Economics: Calculating Real Profit
Revenue climbs but the bank balance does not — the classic sign nobody worked out the full unit economics. A line-by-line breakdown with a concrete worked example.
In short
Marketplace seller unit economics is the product cost minus every real per-unit expense: platform commission, two-way logistics, storage, payment processing, fines, in-platform advertising and tax. The revenue and gross margin shown on a platform dashboard account for almost none of this, which is why sellers often discover a negative margin after committing to a large stock order rather than before.
The platform dashboard shows the wrong number
A standard seller report shows revenue and, at best, platform commission. That looks like profit, but it is not. Between revenue and the money that actually lands in the account sits a long chain of costs, most of which never appear in the main report: two-way logistics, storage, payment processing, compliance fines, the cost of returns, and in-platform advertising.
This is not a theoretical problem. A seller can grow month over month in revenue while losing money on every single unit sold, because growing revenue scales every underestimated cost right along with the income.
The full cost stack
The line items below all need to be subtracted from the sale price to reach real per-unit profit. Not every one applies to every category, but each is worth checking before assuming a product is profitable.
| Cost line | What it covers |
|---|---|
| Product cost | Manufacturing or wholesale cost per unit |
| Platform commission | Category-specific, not a platform-wide average |
| Logistics to warehouse | Delivery of the batch from supplier or factory |
| Inter-warehouse logistics | Relevant for FBO — redistribution across regional warehouses |
| Last-mile logistics | Delivery from warehouse or seller to the end buyer |
| Reverse logistics | Cost of shipping a returned item back |
| Storage | Fee for holding stock in the platform warehouse |
| Payment processing | Fee for processing the buyer’s payment |
| Fines | For packaging, timing or card-content violations |
| In-platform advertising | Boosting the card in platform search and catalogue |
| Tax | Depends on the seller’s registration and tax regime |
A worked example: from price to profit
This is a hypothetical, illustrative example, not a real seller’s data, but the arithmetic is real and shows the mechanism, not specific numbers for your category. Take a product retailing at ₽2,000.
| Line | Amount | Running balance |
|---|---|---|
| Sale price | ₽2,000 | ₽2,000 |
| Product cost | −₽600 | ₽1,400 |
| Platform commission (17%) | −₽340 | ₽1,060 |
| Logistics (both ways, averaged) | −₽180 | ₽880 |
| Storage | −₽40 | ₽840 |
| Payment processing | −₽30 | ₽810 |
| In-platform ads (averaged per unit) | −₽120 | ₽690 |
| Return reserve (15% rate × reverse logistics cost) | −₽45 | ₽645 |
| Final per-unit profit | ₽645 (32%) | — |
Why returns are the silent margin-killer in clothing and footwear
The mechanism is simple and almost always underestimated: a buyer orders one style in three sizes, keeps one, returns two. The seller pays delivery logistics for all three units and return logistics for two, while the report shows only one successful sale. In clothing and footwear categories the return rate can run to a third of orders, and if that is not priced in ahead of time, the margin erodes quietly, one return at a time.
FBO and FBS: where the cost lines differ
Under FBO (fulfilment by operator), stock sits in the platform’s warehouse and a storage line appears that does not exist under FBS (fulfilment by seller). Under FBS storage drops out of the calculation, but operational load appears instead, the seller picking and packing orders themselves, which also needs a monetary value even when it is the owner’s own time rather than a hired employee’s. There is no such thing as free labour in unit economics: counting a product as profitable while ignoring the owner’s time is an easy way to fool yourself.
What to track every month
A full unit economics recalculation is not needed every week. Five monthly numbers are enough to catch a problem in month one instead of month six: real per-unit profit after every cost line, the return rate per SKU, average logistics cost per unit (it moves with platform rates), the month’s total fines, and in-platform ad spend per unit sold, not the raw total ad budget.
Frequently asked questions
Why is revenue growing but profit is nowhere to be seen?
Most often because the profit calculation was sale price minus cost minus platform commission, full stop. Two-way logistics, storage, payment processing, fines, in-platform ads and returns all stay off the page, though together they can eat half or more of the apparent margin. Growing revenue scales those underestimated costs right along with the income, which is why the problem gets more visible with growth, not at the start.
What return rate should go into the calculation?
It depends on the category. In clothing and footwear it is reasonable to plan for a rate approaching a third of orders, especially when buyers order several sizes of the same style. In categories with no size or fit question, electronics, home goods, the rate is usually noticeably lower. The precise figure for a specific product is best pulled from actual sales data after the first few weeks, not a general category benchmark.
Which is more profitable for unit economics, FBO or FBS?
There is no universal answer: FBO adds a storage line but removes order-picking operational load; FBS removes storage but requires the seller’s own capacity and time for packing and shipping, which also has a real cost even when it is the owner’s own time rather than a hired employee’s. The choice depends on the specific product’s turnover, warehouse capacity and staffing, and it is worth checking by calculating both scenarios rather than going on instinct.
How quickly can an unprofitable product be caught?
If real per-unit profit after every cost line, not just revenue, is tracked monthly, the problem is visible within the first full month of sales. Without that practice, unprofitability often only surfaces months later, once stock has already been reordered based on apparent rather than real profit, and the loss scales right along with volume.
Need a hand with this?
We do this work, not just write about it. Describe the task and we will scope it and send a staged estimate.
Related services
- Marketplace consulting: Ozon and WildberriesOn marketplaces it is easy to lose money before the first sale: the wrong platform for the product, a card missing the attributes buyers filter by, a fulfilment scheme that eats the entire margin in logistics. We work through the economics and launch strategy before you go live, not after the damage is done.
- IT consulting and product auditThe most expensive mistakes in software happen before the first line of code: a misread problem, a stack chosen out of a contractor’s habit, and a specification that does not exist. Consulting exists to settle all of that before the development meter starts running: what to build, out of what, at what cost and in which order. The result is a document, not an opinion on a call.
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