How contribution margin works
Gross margin subtracts only cost of goods. Contribution margin goes further and subtracts every cost that scales with each order: payment processing, pick and pack, shipping, and the blended cost of returns. What remains is the true dollars each sale contributes toward fixed costs and profit, and advertising is spent out of that pool. A product with a healthy-looking gross margin can have a thin contribution margin once a 3 percent payment fee, a 9 dollar shipping subsidy, and a 12 percent return rate are counted, and only the contribution number tells you how much you can actually afford to pay for a customer.
A worked example
Take a 90 dollar order. Cost of goods is 36 dollars, so gross margin is 54 dollars or 60 percent. Now subtract the variable costs: 3 dollars in payment fees, 8 dollars in shipping, 5 dollars in pick and pack, and a returns reserve of 6 dollars. Contribution margin is 32 dollars, or about 36 percent. The gross margin said you could spend up to 54 dollars to break even, but the contribution margin says the real ceiling is 32 dollars. Bidding to the gross number would quietly lose money on every marginal sale.
Contribution margin and ROAS targets
Break-even ROAS is order value divided by contribution margin. Using the worked example, break-even ROAS is 90 divided by 32, which is about 2.8, not the 1.67 you would get from gross margin. Setting a target ROAS off gross margin is one of the most common ways an account looks profitable in the platform and loses money in the bank. Contribution margin closes that gap by putting every variable cost into the denominator before you decide what a conversion is worth.
How iClick uses contribution margin
iClick sets ROAS and ACoS targets from contribution margin, not gross margin, so the platform target and the bank statement agree. The method is to build a per-product contribution model that subtracts payment fees, fulfilment, shipping subsidies, and a returns reserve, then derive break-even ROAS from that number and add the profit target on top. It is unglamorous data work, and it is usually the single change that reconciles a great-looking dashboard with disappointing profit.
