Most online store owners look at one figure: ROAS. If it drops below 3, they switch the ads off. If it climbs above 4, they raise the budget. The problem is that ROAS on its own says nothing about whether you actually make money on an order. Two stores with the same ROAS of 3.5 can be one in profit and the other in the red, because they have different margins, different delivery costs and a different number of repeat purchases.
The number you actually need is the customer acquisition cost your store can still bear. That is the ceiling on how much you can pay for one new customer and stay in profit. Once you know it, ad decisions turn from a gut feeling into math.
1. Start from contribution per order, not revenue
Take a store with an average order value of 60 euros and a gross margin of 45 percent. That is 27 euros. From that, subtract the real fulfilment costs: packaging and delivery 6 euros, payment processor fee 1.5 euros. That leaves 19.5 euros per order.
That is your real number. Not 60 euros of revenue, but the 19.5 euros that actually remains before you pay for ads.
2. Calculate the ceiling
If you pay 19.5 euros for a new customer, you are exactly at break-even. That is not the goal. Say you want to earn 6 euros on each order. Your customer-acquisition ceiling is therefore 13.5 euros.
Converted to ROAS: 60 divided by 13.5 is about 4.4. Now you know your threshold is 4.4, not 3, as you thought. Plenty of stores discover the opposite — that their real threshold is 2.2, and that for months they switched off campaigns too early that were actually turning a profit.
3. Include repeat purchases, or you will pay too little
If 30 percent of customers buy again within a year, the average number of orders per customer is about 1.4. So the contribution per customer is not 19.5 euros, but around 27 euros.
That is the difference between being able to afford 13.5 euros per new customer and being able to afford 20. That very difference decides who can aggressively buy ad space in November and who pulls back. If you sell products that repeat (cosmetics, food, supplements), this is your biggest hidden advantage. If you do not calculate it, you hand it to the competition.
4. What this changes about creatives
Once you know the ceiling, you stop judging ads by how much you like them and start judging them by the cost of an acquired customer. In practice that means three things:
- You kill a creative when it crosses the ceiling, not when it stops being interesting to you
- You test several angles at once, because every new angle lowers the average cost per customer
- You stop optimizing for clicks and start optimizing for orders
At Red Eye Monkey we lifted online sales by 400 percent precisely because we set this number first and then built the video ads beneath it. Without a ceiling we would have switched off half our winning creatives too early.
5. Do this today in 20 minutes
Open a spreadsheet and enter five figures: average order value, gross margin in percent, average packaging and delivery cost, payment fee, and the share of customers who buy more than once. From that you get the ceiling. Write it on a sticky note and put it on your monitor. Next time you look at the ad account, you will know in three seconds what to keep running and what to stop.
Most stores we review have this number wrong by more than 40 percent. That is the difference between growth and stagnation on exactly the same budget.
Want to look at your number together? Book a 15-minute call or write to me at jaka@vvvdigital.eu. Tell me your margin and average order, and I will tell you where your ceiling is and what it means for your ads.