A marketplace is often a shop’s largest sales channel and, at the same time, the one where it is hardest to answer a simple question: how much of this do we keep? Revenue is visible straight away, but costs are spread across several settlements at once. This guide brings them together into a single figure (effective commission) and shows how to decide, product by product, what is worth selling on a marketplace and what is better kept in your own shop.
Cost map
What makes up the cost of selling on a marketplace
The sales commission is only the first line of the calculation. The full list of cost streams looks like this:
| Fee type | What it depends on | Where you see it |
|---|---|---|
| Sales commission | product category and selling price | seller settlements |
| Featured and promoted listings | package type and duration | settlements, per listing |
| Marketplace ads | clicks and campaign budgets | ads panel, separate settlement |
| Delivery subsidies (free-delivery programme) | basket value and carrier price lists | settlements, delivery items |
| Fixed fees | subscription, additional services | consolidated invoice |
Rates differ between categories and change over time, so any guide quoting specific percentages goes out of date within a month. The rule that does not go out of date: profitability is calculated from the fees actually charged in settlements, not from the price list. The price list tells you what selling might cost; the settlement tells you what it did cost.
One figure
Effective commission: one figure instead of ten price lists
Working definition
Effective commission is all marketplace fees charged in a period divided by marketplace sales revenue for the same period. A single figure that can be set alongside the product’s gross margin.
Per account it is a curiosity; per listing it is a decision-making tool. This is the breakdown for a tools shop (one month, illustrative data, marketplace revenue €21,000):
Marketplace fees as % of revenue · monthtools shop · illustrative data
The nominal commission (8.2%) is only half the story. The other half is spread across ads, delivery and promotion, items that are easy to overlook because they sit in other tabs of the settlements.
With a gross margin of 38%, this shop gives the marketplace almost half its margin on the products sold there. That can still be good business, but only if it is calculated per listing, because the 16.3% average is made up of listings at 11% and others at 27%.
Channel versus channel
Marketplace or own shop: the per-product calculation
This choice is not made once and for all: it is a calculation repeated per product. On both sides, you subtract the channel’s cost of sale from the product margin: on the marketplace, the offer’s effective commission; in your own shop, the advertising cost (per product where Google Shopping reports it, otherwise the shop’s total ad spend relative to shop revenue) plus payment and delivery handling. Three typical outcomes:
A product people buy “from the marketplace”
Average margin, in a category where customers habitually start their search on the marketplace. Your own advertising would cost more than the effective commission, so the channel earns its keep despite the fees.
A product caught in a price war on the listing
Low margin and price bidding against competitors on the same product page. The effective commission eats what is left of the margin; in your own shop, the same product holds up in bundles and through cross-selling.
A unique product with a high margin
The margin absorbs both the effective commission and the cost of your own advertising. The marketplace adds reach, the shop builds a customer base. One condition: make sure marketplace ads are not bidding on phrases you win anyway.
This calculation requires the product margin per product in your data (purchase price or margin percentage in the shop system). Where to get it and how to connect it is covered in a separate guide on margin in e-commerce data.
Pitfalls
Four pitfalls in calculating marketplace profitability
Calculating with the nominal commission
The category’s list commission can be less than half of the real cost. A calculation without ads, promotion and delivery subsidies produces profitability that exists only in the spreadsheet.
Delivery subsidies spread across the total
A marketplace delivery programme can cost the most on cheap products: the subsidy is similar, but the basket is small. Subsidies must be assigned to orders, not treated as one lump sum.
Ads without a per-offer breakdown
Marketplace ad campaigns averaged across the whole account hide offers where advertising eats the entire margin. Ad spend should be read per offer, next to that offer’s effective commission.
Profitability based on placed, not paid, orders
Cancelled orders manage to incur part of the costs but leave no revenue. The calculation should be based on paid orders, using statuses from the shop system.
DataOrganizer
How DataOrganizer calculates marketplace profit after fees
DataOrganizer pulls orders and charged fees from the marketplace (commissions, promotion, ads, delivery subsidies), and product purchase prices from the shop system. From these it builds the effective commission and profit after fees per offer, category and period. In practice, it looks like this:
The three largest offers after the full calculation:
| Offer | Revenue | Total fees | Effective commission | Profit after fees |
|---|---|---|---|---|
| 108-piece socket set | €3,100 | €457.50 | 14.8% | +€690 |
| 18V cordless screwdriver | €2,450 | €660 | 26.9% | +€100 |
| Workshop organiser | €1,300 | €155 | 11.9% | +€390 |
The screwdriver sells well, but ads and promotion push its effective commission up to 26.9% against a product margin of 31%: just €100 remains from almost €2,500 of revenue. Recommendation: cut back ads on this offer and check its profitability in your own shop before it adds another month of illusory sales.
Methodological note: all amounts in the examples are illustrative and serve to show how the calculation works. Marketplace fee rates depend on the category and change over time; the source of truth is the seller’s settlements and the marketplace’s current price list.
Key takeaway
Effective commission next to product margin: that is the whole tool. When both figures sit beside every offer, decisions about “what stays on the marketplace, what moves back to the shop, where to cut ads” stop being a debate about impressions.
FAQ
Frequently asked questions about marketplace fees and profitability
What makes up the cost of selling on a marketplace?
The sales commission (which depends on the category), fees for featured listings and promotion, ad spend on the marketplace, delivery subsidies under the delivery programme, and fixed fees. The nominal commission is usually less than half of the total cost of sale, which is why the calculation is based on the fees actually charged in the settlements.
How do you calculate the effective commission?
The sum of all marketplace fees in a period divided by marketplace revenue in the same period. It becomes really useful per category and per offer, because differences between products can be several-fold, and they show where the money is leaking.
Is selling on a marketplace profitable?
Per product: yes, if the offer’s product margin is clearly higher than its effective commission. The same catalogue usually contains offers that thrive on the marketplace and others that lose money on every unit despite excellent sales.
How do you compare a marketplace with your own shop?
With the same calculation on both sides: product margin minus the channel’s cost of sale (effective commission versus advertising, measured per product in Google Shopping or as total spend relative to shop revenue, plus payments and delivery). The comparison only makes sense per product and on paid orders; channel averages blur everything of interest.
Where does DataOrganizer get marketplace fees from?
From marketplace settlements via the integration: orders plus charged fees of every type. Once combined with the purchase price from the shop system, the AI assistant answers questions about profit after fees per offer, without manually stitching together three exports.
Cheat sheet for the whole guide
The marketplace calculation in three steps
1. Collect all fees, not just the commission. Commission, promotion, ads, delivery subsidies and fixed fees add up to the effective commission: a single figure comparable with the margin.
2. Go down to offer level. The account average hides both profitable offers and loss-making ones. Decisions on ads, promotion and withdrawing a product are made per offer.
3. Compare channels with the same calculation. Marketplace versus own shop means margin minus cost of sale on both sides, on paid orders. DataOrganizer builds this calculation automatically from marketplace settlements, shop data and margin, so the answer to “how much of this is actually left” takes a single question in the chat.
DataOrganizer · Marketplace sales, fully costed
Connect your marketplace account and shop system: commissions, ads, promoted listings and surcharges are matched with product margin per listing. Demo account available instantly; you only pay for the sources you connect.