To reconcile marketing metrics with contribution margin, start from the ad platform's reported revenue. Remove GST, cancelled and return-to-origin orders, customer returns and discounts to reach net sales. Then deduct product cost, shipping both ways, payment and COD fees and packaging to get contribution before ads, and subtract ad spend last. A 4x ROAS on the dashboard can be a single-digit margin in the P&L.
Marketing teams report what the ad platform shows. Finance reports what the books show. In most D2C businesses the two numbers describe different things, and the gap between them is where profitable-looking brands lose money.
The bridge: from ROAS to contribution (illustrative, per 100 orders placed)
Assumptions: average order value ₹1,180 including 18% GST, 15 orders cancelled or returned to origin, 8 customer returns, product cost ₹400 per unit, forward shipping ₹80, return shipping ₹70, ad spend ₹29,500.
|
Line |
Amount (₹) |
|---|---|
|
Revenue reported by ad platform (100 x ₹1,180) |
1,18,000 |
|
Less GST at 18% |
(18,000) |
|
Less cancelled and RTO orders (15) |
(15,000) |
|
Less customer returns (8) |
(8,000) |
|
Net sales (77 orders kept) |
77,000 |
|
Less product cost (77 x ₹400) |
(30,800) |
|
Less write-off of damaged returns |
(1,000) |
|
Less forward shipping (85 shipped x ₹80) |
(6,800) |
|
Less return and RTO shipping (23 x ₹70) |
(1,610) |
|
Less payment gateway and COD handling fees |
(2,200) |
|
Less packaging (85 x ₹25) |
(2,125) |
|
Contribution before ads (CM2): 42.2% of net sales |
32,465 |
|
Less ad spend (reported ROAS 4.0x) |
(29,500) |
|
Contribution after ads (CM3): 3.9% of net sales |
2,965 |
The dashboard shows 4.0x. The business keeps ₹2,965 from ₹1,18,000 of reported revenue. If the dashboard reports the pre-discount value rather than the sale price, deduct the discounts as well. Returned goods are assumed to be resaleable except those written off.
Break-even ROAS and maximum CAC
Contribution before ads is ₹32,465 for ₹1,18,000 of reported revenue. Break-even ROAS is 1,18,000 / 32,465, about 3.6x. Any campaign below 3.6x on the platform loses money before overheads, even when it looks profitable.
Set a maximum CAC from CM2. Contribution before ads per order placed is about ₹325. If you need a CM3 of at least 15% of net sales (₹770 per order placed, so about ₹115), maximum affordable CAC is about ₹209 per order placed. The current CAC is ₹295, so you must either cut CAC by about ₹86 or raise CM2 through prepaid conversion, lower RTO or better pricing.
CM1, CM2 and CM3 for D2C unit economics
|
Level |
Definition |
Question it answers |
|---|---|---|
|
CM1 |
Net sales minus product cost |
Is the product priced right? |
|
CM2 |
CM1 minus shipping, returns, payment fees and packaging |
Is each order profitable to fulfil? |
|
CM3 |
CM2 minus marketing spend |
Can we afford the way we acquire customers? |
Why platform numbers overstate profit
-
They include GST, which is not your revenue.
-
They count orders placed, not orders delivered and kept.
-
Several platforms claim the same sale, so attributed revenue exceeds actual sales.
-
Returns after the attribution window never reduce reported revenue.
-
COD and prepaid orders look identical, though COD carries higher RTO and handling cost.
The India-specific cash issues
Contribution margin is not cash. COD amounts reach you after the courier remits them, and marketplace payouts arrive after settlement cycles, net of commission, fees and tax deducted at source. This delay is working capital, and the mechanics are explained in our post on why profit and cash diverge. Plan it with a 13-week cash flow forecast. Returns also generate credit notes with GST implications, so check reporting rules on the GST portal. For the contribution formula itself, see Investopedia's explanation.
A monthly reconciliation routine
-
Export ad spend and reported revenue by channel.
-
Pull orders, cancellations and returns from the store or ERP.
-
Match courier RTO reports and payment settlements to the ledger.
-
Rebuild the bridge above for each channel and for the top SKUs.
-
Review CM3 by channel, and cut or cap spend where it is below target.
For founders without a finance team, this is where virtual CFO services and outsourced CFO services with accounts support pay for themselves. CFOSME includes contribution reporting in the InsightTrack MIS. Teams based in Bangalore or Mumbai can also work with our local consultants. To see how growth affects margins at scale, read how growth dilutes unit economics.
FAQs
What is contribution margin for ecommerce?
Contribution margin for ecommerce is net sales minus variable costs: product cost, shipping, returns, payment fees, packaging and, at CM3, marketing spend. It shows what each order contributes toward overheads and profit.
Why does my ROAS look good but my business loses money?
ROAS uses gross reported revenue, which includes GST and orders later cancelled or returned. It also ignores shipping, fees and product cost. Contribution margin includes all of them.
What is a good CM3 for a D2C brand?
It depends on category, repeat purchase rate and CAC payback. Set a target from your own economics, such as the level needed to repay customer acquisition within a chosen number of months, and track it by channel.
How do RTO and returns affect D2C unit economics?
Each RTO or return costs forward and reverse shipping, packaging, possible damage and blocked cash, while the ad spend already incurred earns nothing. COD-heavy orders usually carry the highest cost.
Next step: Talk to CFOSME to reconcile your marketing dashboard with real contribution margin.