Sustainable growth – the 5 most important KPIs in e-commerce

KPIs – Overview with impact

Of course, numbers are not everyone's cup of tea. But if you want to hold your own in e-commerce, you should Key Performance Indicators (KPIs) do not ignore. These key figures give you measurable insights: Where are things running smoothly – and where do you need to go back to the drawing board? They are like a navigation system for your business. You can use them to optimise processes, identify weaknesses and target your investments more effectively.

Particularly exciting: some KPIs show you with just a few clicks whether your marketing measures are working. And the best thing? Most tools such as Google Analytics, HubSpot or Shopify also provide these figures. The five most important KPIs you should know are

• Acquisition costs (CAC)

• Customer value (CLV)

• Conversion rate (CR)

• Average order value (AOV)

• Return rate (RR)

1. acquisition costs (Customer Acquisition Cost – CAC)

Winning customers costs money – that's no secret. But how much exactly? This is where the CAC comes into play. It shows how much you spend on marketing per new customer.

The formula is simple:

Marketing costs : number of new customers = CAC

Online channels in particular offer you the opportunity to analyse exactly where your customers come from – Facebook ads, Google ads or influencer marketing? Not every click leads to a purchase, and not every channel is equally efficient. Therefore: measure, compare, optimise.

A Facebook campaign example:

You spend €1000 and gain 125 new buyers. The result? 8 € CAC

This is your key figure. And this is exactly what helps you make smart budget decisions. But be careful: target group and product influence performance. What works for vegan cosmetics may flop for sustainable furniture. The CAC is not a universal solution – it is a tool that you should interpret individually.

Tip: Set up a small spreadsheet in which you enter monthly CAC per channel. This way you can see trends – and quickly recognise where you can use your budget effectively.

2. customer value (Customer Lifetime Value – CLV)

Customers who come back are pure gold – especially if they are truly connected to your brand. The Customer Lifetime Value (CLV) shows you how much revenue a customer generates during the entire relationship with your shop – minus acquisition costs.

The CLV is not easy to calculate, but any approximation helps. Particularly important: the better your brand is perceived, the more likely it is that customers will come back – and not switch to the competition. Good design creates trust. Good images stay in the mind.

Formula:

Turnover per customer – CAC = CLV.

If you know the CLV, you can also invest more in the initial approach. Because even if the first purchase is not yet a win – in the long term, the connection pays off. A bit like a good first date with potential.

A common mistake: Many people place ads, expect immediate sales and stop everything if it doesn't work right away. Those who keep an eye on CLV, on the other hand, recognise the long-term effect and can invest more courageously.

Tip: When it comes to customer acquisition, it is advisable to plan for the long term instead of taking a short-term view. Calculate your CLV on a quarterly basis. This will give you a feel for how quickly marketing measures pay off – instead of guessing every week.

3. conversion rate (Conversion Rate – CR)

Your shop has 1000 visitors, but only 16 buy something? Welcome to reality – the average conversion rate in e-commerce is 1.6 %, Top shops create about 3.6 %. The question is: How many of the traffic will become real customers?

Everything counts here: shop speed, intuitive navigation, trust seal, product presentation and, of course, the visual language. If your products are visually convincing, the probability of purchase increases immediately. UX (user experience) is not a bonus, but a must.

Tools such as Google Analytics or HubSpot show you where users bounce. Perhaps the checkout form is too complicated or the product images are too meaningless. Maybe there's just a bit of heart missing.

Also exciting: Conversion often differs significantly between desktop and mobile. Many shops perform less well on mobile – yet more and more people are buying on the move.

Tip: Look at your CR per device (desktop vs. mobile). Improve the mobile user journey first – test whether image sizes, texts and CTAs also work on mobile phones. And make sure that your values are directly recognisable.

4. average shopping basket value (Average Order Value – AOV)

The higher the AOV, the better for your sales.

Quite simply:

Total sales : number of orders = AOV.

Example:

If your shop generates €100,000 in sales with 500 orders, the average shopping basket is €200.

But how do you increase this value? Two strategies: Upselling and Cross-selling. Recommend suitable products or higher-quality alternatives – but subtly and stylishly. A visually well-staged bundle is more convincing than a clumsy "buy this too" text.

Well-designed product pages also help. Beautiful photos, comprehensible texts and a clearly structured presentation not only increase trust – they also invite you to browse. This often leads to more items in the shopping basket without being intrusive.

Your design therefore plays a key role in determining how „valuable“ your shop appears. Customers are more likely to buy three products if they feel emotionally engaged – and visual storytelling is your best friend here.

Tip: Test an element in the checkout “You have the lip care –, why don't you try our organic hand cream with it?”. Small addition, big effect on AOV – without being intrusive.

5. return rate (Return Rate – RR)

Now it's getting tricky. The online returns rate in Germany is 4 %, fashion even at 28.5–70 %. Of course, because there are additional reasons here, e.g. product different than expected (approx. 50 %), product damaged (approx. 25 %), alternative ordered (approx. 20 %) or impulse purchase (5 %). Particularly critical: In the 14–29 target group above-average number return – often because the product does not fit or does not meet expectations.

What is often forgotten: Every return is not only a cost factor, but also an environmental problem. Packaging, transport, storage – all consume resources. If you want to sell more sustainably, you have to take countermeasures here.

There are many reasons for returns: unclear sizes, bad photos, damaged products or simply impulse purchases. The solution? Honest, high-quality product presentation, good packaging, clear information. Say how the shoe really turns out – and show how it looks when worn.

Psychological tricks also help: Returns are more frequent with purchase on account than with prepayment. Small incentives such as discounts or give-aways can help to minimise returns – without preventing the purchase.

Tip: Collect specific reasons for returns (e.g. using a return sticker or returns form). This allows you to prioritise your measures – and achieve more with fewer returns.

KPIs are more than just numbers

At first glance, key figures seem sober, but they are extremely valuable. They show you where you are losing money, where you should invest wisely and how you can become more successful in the long term. Instead of just acting on instinct, KPIs give you a solid foundation for strategic decisions.

Be careful not to optimise all KPIs at the same time. Set priorities, try things out, compare channels and keep an eye on long-term developments. Remember: success in e-commerce is not a sprint, but a sustainable marathon – and KPIs are your compass.

You don't just want to optimise KPIs, you want to make your brand really shine?

Then start with what really excites your target group: Product photos that create trust, a Corporate design that creates recognition, and Give-aways that retain customers, even before the shopping basket is filled.

We from 2bu design help you, Visual clarity find your style and create a Building a brand world, that manages without any loud marketing – and still works. Fewer returns thanks to better visualisation, more purchases thanks to emotional imagery and a Design strategy that matches your values.

Sounds good? Then let's see together how we can set up your brand so that your KPIs are also happy – Sustainable, efficient and with substance.