SKU Profitability Analysis for Ecommerce Brands
A product can top your sales report and still leave little money to run the business.
Discounts reduce the selling price. The parcel costs more than expected. Returns generate refunds and extra handling. A product that looks healthy at gross margin can become much less attractive by the time the customer keeps the order.
SKU profitability analysis measures what each product contributes after clearly defined costs, then uses that information to guide pricing, purchasing and operational improvements. The aim is to identify which decisions improve the business, rather than assign every expense to a SKU with false precision.
This guide uses hypothetical USD examples, excluding sales taxes and VAT. They are not client results or industry benchmarks. The core model assumes single-product orders; mixed baskets need a consistent allocation method.
Define the margin you are calculating
Gross margin and contribution answer different questions. Gross margin subtracts cost of goods sold from net sales. Contribution subtracts the variable costs within a defined scope. Neither automatically equals net profit after the whole business’s overhead.
For this guide, we use contribution before acquisition: net product sales, less landed product cost, fulfilment, net outbound shipping, transaction fees and expected return-related costs. Then we show acquisition separately where attribution is defensible.
Labels such as CM1, CM2 and CM3 vary between businesses. Publish your own definitions and use them consistently. CommerceIQ’s reporting guidance also uses SKU-level profitability metrics; your own model must reconcile to the channels and costs you actually operate.
Measure | Working definition in this guide | Decision supported |
|---|---|---|
Net sales | Product revenue after discounts and refunds, excluding tax | What revenue did the product retain? |
Gross profit | Net sales less cost of goods sold | How much remains after product cost? |
Contribution before acquisition | Net sales less the specified variable operating costs | What does the product contribute before ads and overhead? |
Contribution after acquisition | The above less attributable acquisition cost | Does the acquisition scenario leave a contribution? |
Net business profit | Revenue less all applicable business costs | Is the business profitable overall? |
Build a cost record that can be traced
Pull order-line sales, discounts and refunds from the sales platform, then match product costs to the relevant SKU and period. Use the actual landed cost where available, including the appropriate inbound freight and import charges. Keep separate views for accounting treatment and forward-looking decisions when necessary.
Match fulfilment charges to orders and allocate them to products using an explicit rule. A fragile item may drive the box size and labour even if it represents a small share of basket revenue. Allocating everything by sales value can conceal that difference.
Reconcile payment fees, shipping income and outbound postage. If the customer pays $5 for shipping and postage costs $8, show the $3 net subsidy or show both lines separately. Do not omit the income in one view and include it in another.
For refunds and returns, choose a cohort method or a period method and label it. A newly launched product can look unusually profitable before its returns arrive. Estimates should be updated when the cohort matures.
Worked example: where a $60 net sale goes
Assume a simplified product cohort leaves $60 of net sales per originally shipped unit after discounts and expected refunds. Landed product cost is $18 per originally shipped unit after the assumed credit for recoverable returned stock. Expected return handling, reverse freight and other unrecovered return costs add $3, without counting the same refund or product loss twice.
Per originally shipped unit | Illustrative amount |
|---|---|
Net sales after discounts and expected refunds | $60 |
Landed product cost, net of assumed stock recovery | −$18 |
Fulfilment and packaging | −$4 |
Outbound postage less customer shipping income | −$5 |
Payment and transaction fees | −$2 |
Additional expected return-related costs | −$3 |
Contribution before acquisition and overhead | $28 |
Contribution margin before acquisition | 46.7% |
Example defined on an originally shipped-unit basis, with refunds and recoverable stock treated consistently.
The $28 is available to contribute towards acquisition and fixed costs. If attributable acquisition costs were $20 on the same basis, $8 would remain before overhead. It would be wrong to call that $8 net profit unless all remaining costs had been included.
The model’s break-even acquisition spend before overhead is $28 per originally shipped unit. That is not automatically the target CAC. Customer-level CAC and unit-level contribution have different denominators, especially when customers buy several units or make repeat purchases.
Compare contribution dollars as well as percentages
A high contribution percentage on a product that barely sells may generate less money than a lower percentage on a high-volume line. Equally, revenue alone can overstate the value of a bestseller.
Monthly product view | SKU A | SKU B | SKU C |
|---|---|---|---|
Net sales | $120,000 | $48,000 | $36,000 |
Contribution before acquisition | $24,000 | $24,000 | $3,600 |
Contribution margin | 20% | 50% | 10% |
Interpretation | Largest sales, but thin contribution | Same contribution as A on much less sales | Needs investigation before scaling |
Illustrative monthly totals. Advertising and fixed overhead are excluded consistently across all three products.
SKU B is commercially interesting, but that does not mean shifting all demand to it is possible. Consider customer demand, stock availability, product relationships, repeat purchases and supplier capacity before changing the assortment.
Handle advertising without inventing precision
An ad may introduce a customer who buys several items or returns weeks later. Platform-attributed revenue does not necessarily identify the incremental value of a product. Avoid allocating all ad spend to the first product clicked and treating the result as objective SKU economics.
Keep the pre-acquisition contribution view clean. Add a clearly labelled acquisition scenario at order, campaign or customer-cohort level. Where an allocation is necessary, state the method, show the unallocated balance and test whether a different reasonable method changes the decision.
For bundles, compare the bundle’s net revenue and complete fulfilment cost with the components it consumes. A profitable bundle can still create an expensive stockout on a component needed for another high-contribution product.
Use the analysis to choose a practical intervention
Finding | Investigate first | Potential decision |
|---|---|---|
High sales, low contribution | Discount depth, landed cost, parcel cost and returns | Reprice, reduce discounting or fix the cost driver |
Good margin, poor stock availability | Lead times, purchase commitments and forecast assumptions | Protect replenishment if cash and demand support it |
High returns | Reasons by size, quality, product description and cohort | Fix the cause; test the change before scaling |
Slow sales and high stock exposure | Age, demand, carrying costs and liquidation options | Adjust buying and compare clearance choices |
Low direct contribution, strong basket role | Incremental basket value and repeat behaviour | Assess the order and customer effect before removing it |
Model the proposed change. Saving $1 on packaging across 10,000 comparable orders produces $10,000 of direct savings before implementation costs or unintended effects. If damage and returns rise, the net benefit can shrink or disappear.
For stock already purchased, distinguish sunk expenditure from future cash decisions. A clearance choice may be justified even when it recovers less than historical cost. Compare the incremental cash and costs of clearing, holding, bundling or disposing, while finance maintains the appropriate accounting records.
Review the products that change the answer
Start with the highest sales, largest contribution dollars, weakest contribution and highest inventory exposure. Keep the detail available for the full range, but focus the review on products that could materially change the result.
Review monthly, with a shorter exception check after major cost, price, promotion or return-rate changes. Record the owner, action, expected benefit and review date. Reconcile the model’s totals to finance and explain timing or allocation differences rather than quietly forcing the numbers to match.
Connect the resulting purchasing decisions to your demand and cash plan. A commercially attractive product still needs enough funding, supplier capacity and warehouse availability to support growth.
Frequently asked questions
Is contribution margin the same as gross margin?
No. Gross margin subtracts cost of goods sold. A contribution view subtracts the variable costs within its stated definition. Show the cost lines so readers can compare the measures correctly.
Should salaries and software be allocated to each SKU?
You can build a fully allocated view, but keep it separate from contribution. Arbitrary overhead allocations can make a useful product look unprofitable even when removing it would not remove the cost.
How should we treat shipping revenue?
Either show shipping revenue and postage separately or use an explicitly defined net shipping cost. Apply the same treatment across products and reconcile it to the business totals.
Should we discontinue every low-margin SKU?
No. Assess basket effects, customer retention, stock already committed and the costs that would actually disappear. Use the model to identify questions, then test the commercial decision.
Turn the numbers into operating decisions
Onflair helps consumer brands identify margin pressure and put improvements into practice across product costs, suppliers, freight, fulfilment and inventory. Discuss your operation with us if you need to understand which changes will make a meaningful difference.
Author: Anthony Mellor, Onflair. All product figures and charts are illustrative. The cost definitions and decision framework are Onflair’s suggested management approach, not a universal accounting standard.