Gross margin subtracts cost of goods sold from net revenue. It is useful for evaluating product economics and pricing, but it may omit costs that rise with each order, including payment processing, pick-and-pack, outbound shipping subsidies, marketplace fees, and variable customer-service costs.
Contribution margin gets closer to order economics
Contribution margin subtracts the variable costs relevant to the decision being made. Define the layers explicitly: contribution margin 1 might subtract product cost and payment fees; contribution margin 2 might also subtract fulfillment, shipping subsidies, and marketplace fees; a later layer may include variable marketing spend. There is no universal naming convention, so publish the formula.
Choose the right denominator
Calculate margin as a percentage of net revenue, not gross merchandise value, when discounts, refunds, and cancellations are material. Also track contribution dollars per order. A high percentage on a low-value order may contribute fewer dollars than a lower percentage on a larger basket.
Apply the metric to acquisition decisions
A campaign can produce attractive ROAS and still lose money if product margin is thin or fulfillment costs are high. Compare contribution profit after variable marketing cost with the incremental spend required. Keep fixed overhead separate for operating-profit analysis, but do not ignore variable costs simply because they sit outside accounting COGS.
Connect channel reporting to unit economics
Use ThoughtMetric or another attribution source to organize channel performance, then reconcile attributed revenue with finance-approved net sales and cost assumptions. Channel dashboards should show revenue, spend, gross margin, contribution dollars, and contribution margin using documented definitions.
At a glance
| Metric | Typical calculation | Best use |
|---|---|---|
| Gross margin % | (Net revenue − COGS) ÷ net revenue | Product pricing and sourcing |
| Contribution margin % | (Net revenue − defined variable costs) ÷ net revenue | Order and channel economics |
| Contribution dollars | Net revenue − defined variable costs | Comparing absolute value across orders or campaigns |
Frequently asked questions
Is contribution margin the same as profit?
No. It generally subtracts defined variable costs but excludes some fixed operating expenses. It is a decision-making measure, not necessarily net income.
Should ad spend be included in contribution margin?
For evaluating post-marketing contribution, yes. Keep a pre-marketing contribution view as well so teams can distinguish product/order economics from acquisition efficiency.
Which metric should a Shopify store prioritize?
Use both. Gross margin helps manage product economics; contribution margin helps determine whether orders, promotions, and acquisition activity create enough value.
Why can ROAS look good while contribution is negative?
ROAS usually compares attributed revenue with ad spend and may not account for COGS, discounts, refunds, shipping subsidies, fees, or attribution over-credit.
The most reliable measurement system combines consistent definitions, reconciled commerce data, channel diagnostics, and experiments. Review assumptions whenever your store, tracking setup, or marketing mix changes.
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