The 7 Profitability Metrics Every eCommerce Business Must Track

eCommerce businesses are often very good at tracking marketing metrics — cost per click, return on ad spend, conversion rate. They are frequently much less rigorous about tracking the financial metrics that determine whether the business is actually profitable.

The distinction matters because a business can have excellent marketing metrics and still lose money. It can grow revenue dramatically while destroying cash. It can have a strong conversion rate and a terrible margin. Marketing efficiency and financial efficiency are not the same thing.

Here are the seven profitability metrics every eCommerce business should be tracking — and what to do with each.

1. Contribution Margin Per Order

This is the single most important number in eCommerce, and the one most businesses do not calculate correctly.

Contribution margin per order is the revenue per order minus all variable costs directly associated with fulfilling that order:

• Product cost (cost of goods sold)
• Payment processing fees (typically 1.5–2.5%)
• Shipping and fulfilment costs (inbound and outbound)
• Packaging costs
• Returns and refunds (as a percentage of orders)
• Customer acquisition cost for that order (more on this below)

A contribution margin of $30 on an average order value of $100 means $30 of each order is available to cover overhead and generate profit. If your overhead is $50,000 per month and your average contribution is $30 per order, you need to fulfil more than 1,667 orders per month just to break even.

Many eCommerce businesses have never calculated this number and are genuinely surprised by how low it is.

2. Customer Acquisition Cost (CAC)

CAC is the total marketing and sales expenditure in a period divided by the number of new customers acquired in that period.

CAC = Total marketing spend ÷ Number of new customers

If you spent $50,000 on advertising in a month and acquired 500 new customers, your CAC is $100. Whether that is good or bad depends entirely on what those customers are worth to you — which brings us to the next metric.

A common error in CAC calculation is to include existing customer revenue in the denominator. CAC should measure the cost to acquire genuinely new customers, not all revenue.

3. Customer Lifetime Value (LTV)

LTV is the total profit generated by an average customer over the course of their relationship with your business.

A simple LTV calculation:

LTV = Average order value × Average purchase frequency per year × Average customer lifespan (years) × Gross margin

If an average customer buys 3 times per year at an average order value of $80, stays with you for 2.5 years, and your gross margin is 45%, then:

LTV = $80 × 3 × 2.5 × 0.45 = $270

This number tells you the maximum you can rationally spend to acquire a customer and still be profitable over their lifetime.

4. LTV:CAC Ratio

The LTV:CAC ratio is the relationship between what a customer is worth and what they cost to acquire. This ratio is one of the defining indicators of eCommerce business health.

A ratio of 3:1 or better is generally considered healthy — it means every dollar spent acquiring a customer returns three dollars of lifetime value. Below 1:1, you are losing money on every customer you acquire, which is only sustainable if you have a clear path to improving either LTV or CAC.

The ratio also informs how aggressively you should invest in customer acquisition. A business with a 5:1 LTV:CAC ratio should be investing heavily in growth. A business with a 1.5:1 ratio needs to fix the economics before scaling.

5. Gross Margin by Product and by Channel

Not all products and not all sales channels deliver the same margin. Aggregated gross margin can mask significant variation underneath.

A product sold through your own website at full price may deliver 60% gross margin. The same product sold through a marketplace at a 15% commission may deliver only 40%. A product you run at a 30% discount to clear ageing inventory may be delivering 20%.

Tracking gross margin at the product and channel level gives you the data to make informed decisions about:

• Which products to push vs deprioritise
• Which channels are worth the commission or fees they charge
• What discount thresholds you can sustain without destroying margin

In Xero or MYOB, this level of analysis typically requires product coding and channel tagging in your order management system, feeding through to your accounting software. It is worth the setup effort.

6. Return Rate and Cost of Returns

Returns are one of the most significant and under-tracked profit leaks in eCommerce. In Australian apparel, for example, return rates of 20–30% are common. Each return has a real cost:

• Outbound shipping (already spent)
• Return shipping (often covered by the retailer)
• Processing and restocking labour
• Potential write-off if the product cannot be resold at full price

When you calculate contribution margin per order, returns need to be included — either as a per-order reserve or as a portfolio-level adjustment.

Tracking return rate by product, by size (for apparel), and by channel helps identify where the problem is concentrated and where targeted action (better product descriptions, size guides, customer education) can reduce it.

7. Payback Period

Payback period is how long it takes to recover the cost of acquiring a customer through the profit generated from their purchases.

Payback period = CAC ÷ Monthly contribution margin per customer

If your CAC is $120 and a customer generates $30 in contribution per month, your payback period is four months. This matters enormously for cash flow planning — a shorter payback period means your growth is self-funding faster.

Businesses with very long payback periods (12 months or more) need significant working capital to fund growth, because they are continuously investing in customers whose value they have not yet recovered. This is a common cause of the growth-cash paradox discussed elsewhere.

Putting It All Together

These seven metrics, tracked monthly and reviewed seriously, give you a comprehensive view of eCommerce profitability:

1. Are individual orders contributing positively? (Contribution margin per order)
2. What is it costing to acquire customers? (CAC)
3. What are those customers worth? (LTV)
4. Is the economics of acquisition working? (LTV:CAC)
5. Are there margin differences by product or channel that require action? (Gross margin by product/channel)
6. Are returns creating a hidden cost problem? (Return rate and cost)
7. How quickly are you recovering your acquisition investment? (Payback period)

If you cannot answer all seven questions with current, accurate data, your financial reporting is not yet giving you what you need to run the business well. That is a gap worth closing — and usually a more valuable use of finance improvement time than adding another dashboard tab.