# Profit per Channel: How to Measure True Marketplace Margins

URL: https://ecomchannels.com/insights/profitability-per-sales-channel/
Category: Finance & reconciliation
Updated: 2026-10-30

> How Australian multichannel retailers can measure contribution margin per sales channel, including fees, ads, freight, returns and payment costs.

To measure profit per sales channel, calculate contribution margin for each one: net sales after refunds, minus cost of goods, marketplace or payment fees, advertising, freight and packaging, and returns costs. Comparing that margin, in dollars and as a percentage of sales, shows which channels actually make money and which only add revenue. The calculation is simple; the hard part is getting accurate, order-level fee and refund data from every channel, which is why reconciliation comes first.

## Why revenue is the wrong scoreboard

Marketplaces are now central to Australian online retail. Australians spent [$18.9 billion through pure online marketplaces in 2025, up 13%, almost a quarter of all online spending](https://auspost.com.au/business/grow-your-business/business-ideas-blog/marketplace-growth-strategy), and 69% of Australians use marketplace apps compared with 78% who shop on retailer websites (Australia Post, 2026). In 2024, marketplaces [drove 39% of online spend growth](https://auspost.com.au/content/dam/auspost_corp/media/documents/ecommerce-reports/annual-ecommerce-reports/ecommerce-report-2025.pdf) (Australia Post, 2025).

That makes adding channels attractive, but each one has a different cost structure. A channel with high sales and high fees, heavy advertising and frequent returns can contribute less than a smaller, cheaper one. Without channel-level margin, growth decisions are guesswork.

## The costs to include for each channel

**Cost of goods.** Landed cost per unit: product, inbound freight, duty and any packaging specific to the channel.

**Selling fees.** Commission, fixed per-order fees, subscriptions and closing fees. On Amazon AU, referral fees are [charged on the total sales price including delivery, and vary by category](https://sellercentral.amazon.com.au/help/hub/reference/external/G200336920), on top of a $49.95 monthly Professional plan fee (Amazon Seller Central, 2026). On eBay, Australian sellers under [AU$25,000 in sales over 12 months and without a Pro plan pay no transaction fees](https://www.ebay.com.au/help/selling/selling-fees/selling-fees-managed-payments-sellers?id=4822), while larger sellers move to Pro plans with transaction fees (eBay Australia, 2026). Use your actual deducted fees, not the rate card. See [hidden marketplace fees](https://ecomchannels.com/insights/hidden-marketplace-fees-australian-sellers/) for what the rate card leaves out.

**Payment costs.** For your own store: card, wallet, PayPal and BNPL fees. Marketplaces usually include payment processing in their fees.

**Advertising.** Sponsored listings and marketplace ads, plus any off-platform ads that send traffic to that channel.

**Fulfilment and freight.** Pick, pack, labels, carrier costs and any marketplace fulfilment fees. Free-shipping thresholds and marketplace delivery promises can change this a lot between channels.

**Returns and disputes.** Refunded sales, refund fees, return freight and written-off stock. In the US, retailers expected [16.9% of 2024 sales to be returned](https://nrf.com/media-center/press-releases/nrf-and-happy-returns-report-2024-retail-returns-total-890-billion) (NRF, 2024), and each card chargeback costs merchants an [average of $128 in fees and internal costs](https://www.mastercard.com/us/en/news-and-trends/Insights/2025/what-s-the-true-cost-of-a-chargeback-in-2025.html) (Mastercard, 2025). Return rates differ by channel, so measure your own.

## A worked example

The figures below are illustrative only, for a single $100 product (excluding GST) sold on two channels:

| Per order | Channel A (marketplace) | Channel B (own store) |
|---|---|---|
| Net sale | $100.00 | $100.00 |
| Cost of goods | $45.00 | $45.00 |
| Selling or payment fees | $13.00 | $2.00 |
| Advertising | $6.00 | $14.00 |
| Freight and packing | $10.00 | $10.00 |
| Returns allowance | $3.00 | $5.00 |
| **Contribution margin** | **$23.00** | **$24.00** |

The marketplace looks expensive on fees but cheap on traffic; the own store is the opposite. Only by putting every cost on the same line do you see they are close, and which levers to pull on each: reduce ad spend on the store, or move freight-heavy items off the marketplace.

## Turning margin into decisions

Once you have contribution margin by channel, and ideally by SKU within each channel, you can:

- **Set channel-specific prices** that hold your target margin after that channel's fees.
- **Allocate stock** to channels with the best margin when inventory is limited, such as during peak season.
- **Cut or fix loss-making SKUs** on specific channels, for instance bulky items where freight eats the margin.
- **Choose the next channel** with a realistic margin model rather than headline commission rates.
- **Set advertising budgets** based on margin after ads, not on revenue.

Review monthly, as part of your [month-end close](https://ecomchannels.com/insights/ecommerce-month-end-close-checklist/), and after any marketplace fee change.

## Key figures

- [$18.9 billion was spent through pure online marketplaces in 2025](https://auspost.com.au/business/grow-your-business/business-ideas-blog/marketplace-growth-strategy), up 13% year on year (Australia Post, 2026).
- [69% of Australians use marketplace apps; 78% shop on retailer websites](https://auspost.com.au/business/grow-your-business/business-ideas-blog/marketplace-growth-strategy) (Australia Post, 2026).
- Marketplaces [drove 39% of online spend growth in 2024](https://auspost.com.au/content/dam/auspost_corp/media/documents/ecommerce-reports/annual-ecommerce-reports/ecommerce-report-2025.pdf) (Australia Post, 2025).
- Chargebacks cost merchants an [average of $128 each](https://www.mastercard.com/us/en/news-and-trends/Insights/2025/what-s-the-true-cost-of-a-chargeback-in-2025.html) (Mastercard, 2025).

## How eComChannels helps

Channel profit depends on accurate cost data per order. [eComChannels Finance auto reconciliation](https://ecomchannels.com/products/finance-reconciliation/) matches each marketplace settlement to orders and records the fees, refunds and adjustments actually charged, so your selling-fee and returns lines use real numbers. [eComChannels order management](https://ecomchannels.com/products/order-management/) holds orders and stock from Amazon, eBay, Kogan, BIG W Market, Bunnings Marketplace, your Shopify or WooCommerce store and other channels in one place, giving a single base for margin reports by channel and SKU.

[eComChannels AI auto shipping](https://ecomchannels.com/products/ai-shipping/) records the label cost for each order across Australia Post, StarTrack, CouriersPlease and Allied Express, so freight is assigned to the right order and channel instead of being averaged. Together, they show which channels and products earn their place, so you can put stock and ad spend where margin is highest. [Book a demo or start a 30-day free trial](https://ecomchannels.com/book-a-demo/).

## FAQ

### What is the difference between gross margin and contribution margin?

Gross margin is sales minus cost of goods. Contribution margin also subtracts the variable costs of selling through a channel, such as fees, ads, freight and returns, so it is better for comparing channels.

### Should I allocate fixed costs like rent and wages to channels?

For channel decisions, start with contribution margin, which excludes fixed overheads. Allocating fixed costs can be useful later, but the allocation method can distort comparisons.

### How often should I review channel profitability?

Monthly is a good rhythm for most retailers, plus whenever a marketplace changes its fees or you change pricing or shipping policies.

## Sources
- Why marketplaces are a powerful growth channel, Australia Post (2026): https://auspost.com.au/business/grow-your-business/business-ideas-blog/marketplace-growth-strategy
- Australia Post eCommerce Report 2025, Australia Post (2025): https://auspost.com.au/content/dam/auspost_corp/media/documents/ecommerce-reports/annual-ecommerce-reports/ecommerce-report-2025.pdf
- Selling on Amazon fee schedule, Amazon Seller Central Australia (2026): https://sellercentral.amazon.com.au/help/hub/reference/external/G200336920
- Selling fees without a Pro plan, eBay Australia (2026): https://www.ebay.com.au/help/selling/selling-fees/selling-fees-managed-payments-sellers?id=4822
- What is the true cost of a chargeback for businesses?, Mastercard (2025): https://www.mastercard.com/us/en/news-and-trends/Insights/2025/what-s-the-true-cost-of-a-chargeback-in-2025.html
- NRF and Happy Returns Report: 2024 Retail Returns to Total $890 Billion, National Retail Federation (2024): https://nrf.com/media-center/press-releases/nrf-and-happy-returns-report-2024-retail-returns-total-890-billion