Ecommerce KPIs are the key metrics that show whether an online store is healthy and growing, such as conversion rate, average order value, customer acquisition cost, contribution margin, and lifetime value. The right KPIs measure profit and retention, not just traffic and total sales.
The core ecommerce KPIs
Conversion rate. The share of visitors who buy. Small improvements compound across all your traffic. (See our guide on conversion rate optimization.)
Average order value (AOV). The average amount spent per order. Raising it through bundles, upsells, or free-shipping thresholds lifts revenue without new customers.
Customer acquisition cost (CAC). What it costs, on average, to get one new customer. If CAC climbs above what a customer is worth, growth becomes unprofitable.
Contribution margin. What is left from a sale after the variable costs of that sale. It tells you how much you can afford to spend to acquire a customer.
Lifetime value (LTV). The total profit a customer generates over the whole relationship, not just the first order. Healthy brands compare LTV to CAC; a common target is an LTV at least three times CAC.
Blended MER. Total revenue divided by total marketing spend across all channels. It tells the truth about marketing efficiency that channel-level ROAS often hides.
Repeat purchase rate. The share of customers who buy again. Repeat customers cost almost nothing to bring back, so this is one of the strongest signals of a durable business.
Cart abandonment rate. The share of shoppers who add to cart but do not buy. A high rate points to friction in checkout, shipping cost surprises, or trust gaps.
Vanity metrics vs real metrics
Impressions, reach, follower counts, and raw clicks feel good but do not pay the bills. They can rise while profit falls. The KPIs above are harder to inflate because they tie back to money kept, not attention earned. When a report leads with impressions and buries CAC, that is usually a sign the real numbers are not flattering.
How the KPIs connect
They form a chain. Traffic times conversion rate equals orders. Orders times AOV equals revenue. Revenue minus variable costs equals contribution margin. Contribution margin has to cover CAC for acquisition to be profitable, and LTV has to beat CAC for the business to compound. Pull one lever and the others move, which is why you watch them together rather than in isolation.
Which KPIs to watch first
If you only track a handful, start with conversion rate, contribution margin, CAC, and repeat purchase rate. Those four cover whether your site sells, whether each sale makes money, whether acquisition is affordable, and whether customers come back. Almost every other metric is downstream of these.
How we use KPIs at Easy Ecommerce Group
We build reporting around profit and retention, not vanity numbers. Every campaign and experiment is judged against contribution margin, CAC, and blended MER, so the dashboard tells you whether the business is actually getting healthier, not just busier.
FAQ
What is the most important ecommerce KPI? There is no single one, but contribution margin and CAC together come closest, because they decide whether growth is profitable. Conversion rate and repeat purchase rate are close behind.
What is a good LTV to CAC ratio? A common benchmark is 3 to 1, meaning a customer is worth at least three times what it cost to acquire them. Below 1 to 1, you lose money on every customer.
How often should I review my KPIs? Watch core metrics weekly for trends and review the full set monthly. Daily numbers are too noisy to act on reliably.
Are vanity metrics ever useful? They can be early signals of awareness, but they should never be the headline. Always pair them with a profit or retention metric so they cannot hide a failing business.
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