The three KPIs that save e-commerce shops
I see it again and again: Online shops make their decisions based on gut feeling. Advertising budgets are somehow distributed, campaigns are launched because "that's just how it's done," and prices are adjusted because it feels right. But no one really knows what works and what doesn't. In the end, you wonder why growth stagnates or profits melt away.
But the thing is actually clear: In e-commerce, data is not just nice to have – it is the foundation for everything. Without knowing the key metrics, you're flying blind. And three of them are particularly crucial for whether your shop survives or really takes off.
1. Customer Acquisition Cost (CAC) – How much does it really cost you to acquire a new customer?
The CAC simply shows you how much money you need to spend to acquire a new customer. That includes all costs: advertising, marketing, tools, agencies, sales staff – everything.
Why should you care? Because this value shows how expensive your growth is. If the CAC keeps rising, you can generate as much revenue as you want – in the end, marketing will eat away your profits.
My tip: Take a close look at which advertising channels have which CAC. If a channel costs you too much, turn it off and invest the budget in the channels that perform better. Sounds logical, but many still don't do it.
2. Customer Lifetime Value (CLV) – What does a customer bring you in the long run?
The CLV tells you how much money a customer brings in during their entire time with you – not just from the first purchase, but overall.
Why is this important? Only when you consider CLV and CAC together do you see whether your business is functioning at all. If your CLV is high, you can also spend more on acquiring new customers and still grow profitably.
My tip: Don't just focus on new customers. With good email campaigns, thoughtful cross-selling, and incentives for repeat purchases, you can get more out of existing customers – without having to pay extra for marketing.
3. Conversion Rate (CR) – How many visitors become buyers?
The conversion rate shows you what percentage of your visitors actually buy or perform another desired action.
Why should you care? Because a better conversion directly means more revenue – with the same traffic. You don't need new visitors; you just make more out of those who are already there.
My tip: Take a close look at where people drop off in the checkout process. Often, it's the little things: too many form fields, slow loading times, or unnecessary distractions. These optimizations often yield surprisingly significant results.
In the end, the numbers count
These three KPIs are interconnected. It's not enough to just keep an eye on one of them. A low CAC is of no use if no one buys a second time. And a high CLV is of little value if your conversion is miserable.
Successful e-commerce companies don't measure these values occasionally – they do it constantly. Those who understand them and actively work with them replace guessing with real control. And make growth predictable instead of random.