If you have an online store, you already know: selling online is not magic. It’s not enough to upload products and wait. Real growth demands strategy, analysis, and ongoing optimisation.

But with so much data available, a key question arises: Which metrics truly matter when scaling an eCommerce business? Below, we outline the 6 essential KPIs you must keep under control in your online store.

1. Retention Rate: Do Your Customers Return to Buy Again?

Acquiring a new customer can cost up to 5 times more than retaining an existing one. That’s why this KPI is not optional; it’s vital.

A strong retention rate shows that your store is not only selling but also building loyalty. If you notice that customers aren’t coming back, it’s time to strengthen your retention strategies, such as:

  • Loyalty and reward programmes.
  • Personalised email marketing campaigns.
  • Good post-purchase service.

2. Conversion Rate: Lots of Traffic, Few Sales = Alert

You may have thousands of visitors each month, but if they aren’t converting, something is wrong. The conversion rate measures what percentage of your visitors end up making a purchase. What’s a good benchmark? Aim for at least 2–3%, though this can vary depending on your niche.

How to improve it:

  • Optimise your site’s user experience (UX).
  • Simplify the checkout process.
  • Build trust with testimonials, clear policies, and guarantees.

Interested in delving deeper into this topic? We recommend our article on 9 tips for increasing conversion in an eCommerce.

3. AOV (Average Order Value): Sell More with Every Purchase

AOV measures how much each customer spends on average in your store. The higher it is, the better your profitability per transaction.

Strategies to improve your UPT:

  • Offer bundles or discounted packs.
  • Use effective upselling and cross-selling techniques.
  • Provide incentives for minimum purchases.

4. UPT (Units per Transaction): Multiply Your Revenue Without More Traffic

This KPI shows how many products are bought per order. The more items each customer adds to their cart, the more your revenue grows—without increasing acquisition costs.

Strategies to improve your UPT:

  • Purchase promotions, such as “Buy 2, get 1 at a discount.
  • Smart suggestions for complementary products.
  • Personalised digital merchandising strategies.

5. Cart Abandonment Rate: The Silent Enemy

Did you know that 70% of carts are abandoned before checkout is completed? It’s an alarming percentage, but it can be solved.

Main causes:

  • Unexpected costs at checkout.
  • Limited payment methods.
  • Long and confusing forms.

What to do?

  • Be transparent about costs from the start.
  • Offer multiple payment options.
  • Implement a simplified and mobile-friendly checkout.

Return and Exchange Rate: What Are Your Customers Telling You?

A high return rate can be a red flag. It not only leads to increased logistical costs but also signals a poor shopping experience that can damage your brand’s reputation.

Analyse the following points:

  • Are your product descriptions and images clear and realistic?
  • Does the product quality match what’s promised?
  • Are you effectively managing customer expectations?

An easy returns process helps build trust—absolutely. But if returns become too frequent, it’s time to review your catalogue, product listings, or even your suppliers.

These 6 eCommerce KPIs are like the dashboard of your online store. They show you what’s working, what needs adjusting, and where to focus your efforts.

But be careful: it’s not just about measuring, it’s about acting on those data points for continuous improvement. At Jelliby, we’ve been helping online stores scale for years with data-driven, UX-focused, and conversion-centric strategies.

Discover our eCommerce optimisation and 360º digital marketing services.