Meta says 3,8. Google says 4,2. TikTok claims its share too, and yet the month's profit looks exactly as tired as it did before you scaled the budgets. The suspicion behind your search is correct: profit after ad spend is a number none of the ad dashboards can give you, not because they hide it but because each one only knows its own slice and all of them count generously. This post shows the arithmetic that cannot lie to you: one subtraction, blended across everything you spend, plus the one ratio your own margin sets that tells you whether any of it is working.
- Each platform attributes every conversion it can plausibly claim, windows overlap, and the claimed revenues routinely add up to more than the store took. Their numbers answer their questions.
- The blended method has one numerator and one denominator: all revenue against all spend from the platforms' billing pages. Nothing can be counted twice.
- On the example store, €15.000 of monthly spend across 706 orders is €21,25 per order: contribution falls from €44,68 to €23,43 the moment advertising is honestly charged.
- Your margin sets a floor: below a MER of about 1,90 on that store, every ad euro is being paid for out of overhead, whatever any dashboard celebrates.
Why the dashboards cannot answer a profit question
An ad platform's reported return is attributed revenue divided by spend, and attribution means the platform's own model deciding which orders it caused within windows it chose. Every platform runs this claim independently, the windows overlap, and a customer who saw two channels is counted by both. None of this is cheating; each dashboard answers its own question honestly. But add the claims and they exceed reality, which disqualifies all of them from the question you asked. The full taxonomy of which ratio answers what is in MER, POAS or ROAS; here we only need the honest one.
The blended method: one subtraction that cannot double-count
Take the month's real revenue from your own store, net of VAT and refunds. Take the month's real spend from every platform's billing page, the surface that charges your card, not the one that celebrates conversions. Divide spend by orders and you have the advertising cost every order actually carried, whatever channel claims it. The example store the calculators use makes it concrete: €15.000 of spend across 706 orders is €21,25 per order, against orders that contribute €44,68 after goods, parcel and fees.
| Line | Amount | |
|---|---|---|
| 25 | Contribution after goods, parcel, fees | €44,68 |
| 27 | Blended ad spend per order | −€21,25 |
| 29 | Contribution after advertising | €23,43 |
| 31 | A day's share of fixed costs (€7.000 ÷ 30) | −€233,33 per day |
| Orders per day that must clear it | about 10 |
Read the last two rows together: at €23,43 after ads, roughly ten orders a day pay the fixed block before the eleventh earns anything. That framing, orders-to-cover rather than a ratio, is what makes the blended number operational instead of decorative.
The MER floor your own margin sets
There is one more number worth computing, because it converts margin into a spending rule. Divide net revenue by contribution before ads, and you get the revenue every ad euro must generate just to cover the goods, the parcel and the fee of the orders it brings: on the example store, about 1,90. A blended MER above the floor means advertising is building profit; below it, ads are consuming overhead no matter what any platform reports. The MER and POAS calculator computes your own floor from five inputs, and it is the single best pre-scaling check that exists.
Judging platforms without attribution
Blended numbers answer whether the whole machine pays; they deliberately do not say which platform deserves the credit, and pretending otherwise is how attribution tools sell. What an operator can do honestly is the marginal test: change one platform's budget meaningfully, hold everything else for two weeks, and watch the blended line. It is slow and it is honest, which is the right trade at €0-10M. What a first order may profitably cost also depends on repeat behaviour, which is a customer acquisition cost question rather than a channel one.
The after-ads checklist
- Pull one month of spend from every platform's billing page and total it; this number, not any dashboard's, is what the month paid for advertising.
- Divide by the month's orders for your blended cost per order, and put it beside your contribution after goods, parcel and fees.
- Compute your floor: net revenue over pre-ad contribution. Memorise it; it changes only when your margins do.
- Read your blended ratio against the floor weekly, on the same weekday, and judge changes over two-week windows, never single days.
- When testing a channel, move one budget at a time and watch the blended line, not the channel's own report.
Three questions that always come next
Is a 3x return good? Unanswerable as asked, immediately answerable against your floor: a store with the example numbers needs 1,90 to break even on variable costs, so 3x is genuinely building profit, while a store with thin margins can lose money at 4x. The ratio only means something next to the margin that has to pay for it.
Which platform should I cut? The blended method will not name one, and that honesty is worth keeping; run the marginal test instead of buying a model that answers confidently. Most stores discover their platforms are closer in true performance than the dashboards' self-reports suggested.
My agency shows profitable campaigns; why is the month flat? Ask one question: what is the denominator, and whose revenue number is in the numerator? Campaign-level attributed profit and month-level blended profit can disagree indefinitely, and the bank sides with blended; if the month still feels wrong after that conversation, the drain may be timing rather than ads, which is walked in making sales but no money in the bank.
Where this ends up
Profit after ad spend is one subtraction on numbers you already own, kept honest by refusing double counting. Do it monthly by hand and you will already argue better with every dashboard; a Shopify profit tracker does it nightly, per day, with spend pulled from the platforms and every euro on the day it was spent, which turns the ratio conversation into a margin conversation, where it always belonged.