The numbers that run your store (and the ones that lie to you)
Revenue flatters. Gross margin flatters. Here are the figures that actually tell the truth, in plain English.
Open most ecommerce dashboards and you drown. Dozens of metrics, all blinking for attention, most of them noise. After twenty years of staring at these screens, I have come to think only a handful of numbers actually run a store, and a few of the popular ones quietly lie to you. Three ideas sit underneath everything that follows. Revenue flatters, but contribution and cash tell the truth. The ad platforms grade their own homework, so trust blended numbers. And keeping a customer beats finding a new one, every single time.
Revenue is vanity. Contribution is sanity.
Revenue feels like the score, but it is the most misleading number you own. A £40 order is not £40 of anything useful. What matters is what survives the costs that move with each sale. Start with gross margin, the profit in the product before any selling costs. Useful, but it flatters, because it ignores shipping, payment fees, packaging and fulfilment. Strip those out too and you reach contribution: the actual cash an order throws off. This, not gross margin, decides whether you can afford to advertise. I have watched “profitable” brands with healthy gross margins lose money on every order once the real costs went in. If your contribution per order is thin, no amount of ad spend saves you; it just helps you lose money faster.
What it really costs to win a customer
Once you know what an order is worth, you can ask what you can afford to pay to win one. Your CAC, the cost to acquire a customer, is the honest version of that, counting all your spend, not the flattering “cost per purchase” a platform reports. And judge your ads the same blunt way you would judge an agency: on blended ROAS, all revenue over all spend, not the platform’s self-graded figure. Scaling on platform ROAS is how brands grow themselves broke. They pour money in, the dashboard glows, and the bank account empties.
The cheapest growth you are ignoring
Most small brands are wildly over-invested in finding new customers and under-invested in keeping the ones they have. Two numbers expose it. Your repeat purchase rate, the share of customers who come back, is the clearest sign of whether you have built a brand or just a stream of one-time buyers. And your email and SMS share of revenue shows how hard your owned audience, the people you do not pay to reach again, is working for you. For most founders it is a fraction of what it could be, which is the good news: it is the cheapest revenue you will ever find. Put the two together and you get lifetime value, the profit (not the revenue, please) a customer brings over time. Set that against your CAC and the ratio tells you whether the model works. As a rough guide, below about three to one is a warning light, though it shifts by category and stage.
The silent killer
Here is the one that kills profitable businesses: cash trapped in stock. You can be making money on paper and still go under, because every pound sitting in unsold inventory is a pound you cannot use. Inventory turnover, how many times a year you sell through your stock, is the early warning. Low turnover is money asleep on shelves. Watch both ends, too: stockouts cost you sales, dead stock costs you cash, and they hurt in opposite directions.
The only number that matters in the end
Strip it all back and one gap defines the business: the difference between what comes in and what you actually keep. Revenue is vanity. A smaller, more profitable business beats a bigger, loss-making one every time, and most founders only learn that the expensive way. So do not try to track everything. Track contribution, blended efficiency, repeat rate, and cash. Get those four honest and the decisions get easier.
You do not need a finance degree for any of this, and you do not need to do the maths by hand. The free Ecommerce Diagnostic works it out from a few inputs: your real margins, your true cost to win a customer, and where the money is leaking. If you would rather someone read it with you and tell you where to start, that is what a Growth Audit is for. Either way, stop scaling on gut. info@meandecisions.com.