Marketing intelligence
Contribution Margin After Ad Spend: Are Your Ads Actually Profitable?
The one metric that shows whether ad spend is adding profit, with a worked example where revenue grows but profit falls.
Contribution margin after ad spend is the money left from your sales after you pay for the products, the variable costs of delivering each order, and your advertising. If it's positive and growing, your ads are adding profit before fixed costs like salaries and rent. If revenue grows while it shrinks, the extra ad spend is buying sales at a loss. ROAS on its own can't show you this.
The formula
Contribution margin after ad spend = Net revenue − Cost of goods − Variable order costs − Ad spend
| Input | What to include | Common mistake |
|---|---|---|
| Net revenue | Sales after cancellations, refunds and discounts, excluding VAT | Using gross sales or including VAT |
| Cost of goods (COGS) | Landed cost of the products sold | Using the purchase price without freight and duties |
| Variable order costs | Shipping, packaging, payment gateway fees, COD fees, return handling | Forgetting COD collection fees and failed-delivery costs |
| Ad spend | All paid media for the period, converted to one currency | Leaving out influencer fees paid outside ad platforms |
Keep fixed costs out of this metric. Salaries, rent and software belong lower in the profit and loss statement. Contribution margin answers a narrower question: does each additional order, after the ads that brought it, leave money to cover those fixed costs?
A worked example
The figures are illustrative, for one month, in AED.
| Line | Amount (AED) | % of net revenue |
|---|---|---|
| Net revenue | 190,000 | 100% |
| Cost of goods | −76,000 | 40% |
| Shipping and fulfilment | −15,200 | 8% |
| Payment and COD fees | −5,700 | 3% |
| Contribution before marketing | 93,100 | 49% |
| Ad spend | −60,000 | 31.6% |
| Contribution after ad spend | 33,100 | 17.4% |
Blended ROAS is 190,000 ÷ 60,000 = 3.17. On its own, that number says nothing about whether 3.17 is good. The margin line does: the store keeps AED 33,100 to cover fixed costs.
Your break-even ROAS
With a 49% contribution margin before marketing, each AED 1 of ad spend must bring in at least:
Break-even ROAS = 1 ÷ 0.49 ≈ 2.04
Below 2.04, ads lose money at the contribution level. This is the same logic as the planning example in how to track blended ROAS and MER, now worked through from real cost lines. Your break-even depends entirely on your own margins, which is why a universal "good ROAS" benchmark is misleading.
When more revenue means less profit
Now say the team raises ad spend by AED 20,000, to 80,000, and revenue grows by AED 30,000, to 220,000. Revenue is up 15.8%, and blended ROAS of 2.75 is still above break-even. It looks like a success.
| Before | After | |
|---|---|---|
| Net revenue | 190,000 | 220,000 |
| Contribution before marketing (49%) | 93,100 | 107,800 |
| Ad spend | 60,000 | 80,000 |
| Contribution after ad spend | 33,100 | 27,800 |
Profit fell by AED 5,300. The extra AED 20,000 of spend brought in only AED 30,000 of extra revenue, so its marginal ROAS was 1.5, well below the 2.04 break-even. The average still looks healthy because the earlier, more efficient spend carries it.
It's an easy pattern to miss, because every headline number goes up. To catch it, look at what the last increase in spend returned, not only at the average for the month.
How to track it weekly
- Fix your cost rates. Agree COGS %, shipping cost per order and fee rates with finance, and update them monthly.
- Pull net revenue from the store, not from ad platforms. For Salla stores, the weekly Salla KPIs cover the revenue side.
- Add total ad spend from every platform.
- Report three lines: contribution before marketing, ad spend, and contribution after ad spend. Show them as a trend over at least 8 weeks.
- When spend changes, calculate marginal ROAS: the change in revenue ÷ the change in spend versus the previous comparable period.
For cash-on-delivery stores, use delivered revenue and include failed-delivery costs. Our Egypt guide to blended CAC and COD return rates shows how to estimate them.
FAQ
Is contribution margin the same as gross margin?
No. Gross margin usually subtracts only the cost of goods. Contribution margin also subtracts the variable costs of fulfilling each order, such as shipping and payment fees. Contribution margin after ad spend then subtracts advertising as well.
Should I calculate it per channel?
Only at the business level, at first. Per-channel contribution needs a reliable way to assign orders to channels, and platform attribution overlaps. Start with the whole business, then use tests or tracked orders to compare channels.
Next step
The e-commerce marketing report template has room for these three lines next to your channel data. AKM connects store data and ad accounts for e-commerce teams, so net revenue and total ad spend come from one place each week. Your cost rates stay in your own sheet.