Contribution Margin vs Gross Margin for Paid Ads: Which Should You Use?

Gross margin and contribution margin are related, but they answer different questions. For paid advertising, contribution margin is often the more useful decision metric because it can include variable costs that happen each time an order is generated.

Gross margin starts with product economics

Gross margin typically focuses on revenue minus cost of goods sold. It is useful for understanding product economics, but it may not capture every variable cost created by an incremental ecommerce order.

Contribution margin goes further

Contribution margin can subtract costs such as payment processing, fulfillment, shipping subsidies, marketplace fees and expected return costs. Those deductions change how much money is available to pay for advertising.

Why the distinction changes break-even ROAS

If gross margin is 60% but additional variable costs reduce contribution margin to 45%, using 60% would produce an overly optimistic break-even estimate. Use the Break-Even ROAS Calculator to model the fuller cost structure.

Calculate margin before judging campaign ROAS

The Profit Margin Calculator helps with basic revenue, cost, profit margin and markup. For ad decisions, extend the thinking to all meaningful per-order variable costs.

Use one definition consistently

Teams often disagree because finance, ecommerce and media buyers use the word “margin” differently. Document exactly which costs are included before setting targets or comparing channels.

Frequently asked questions