INSIGHTS / DIGITAL & PERFORMANCE
ROAS is up and profit is down. What the report leaves out.
A higher return on ad spend does not guarantee a healthier business.
ROAS answers one narrow question: how much attributed revenue came back for each unit of advertising spend. It does not say how much money remained after the order.
What ROAS does not count.
It leaves out the cost of goods, discounts, payment and platform fees, shipping and fulfilment, returns and refunds, and the cost of the agency and creative work. It also says nothing about who bought: a new customer, or someone who would have bought anyway.
A campaign can show a stronger ROAS because it is reaching existing customers or selling discounted products. The attributed revenue improves while the profit the spend actually created falls.
Ask who produced the revenue.
If paid media claims revenue from customers who would have purchased anyway, ROAS overstates the role of the channel. Separate new customers from returning ones, and compare the platform's attribution with how the whole business performed over the same period.
Watch the promotional mix too. ROAS can rise because a deeper discount improves conversion. If margin falls faster than conversion improves, the business may be buying revenue. The same happens when free-delivery thresholds or bundles are set without knowing what each order contributes.
ROAS and MER answer different questions.
| Measure | How it is calculated | What it is good for |
|---|---|---|
| ROAS | Attributed revenue ÷ advertising spend | Comparing campaigns, channels and creative within one attribution system |
| MER | Total revenue ÷ total marketing spend | A blended view of the business, without the argument over which channel gets credit |
MER can mislead as well. It can improve while new-customer acquisition weakens, especially for a mature brand with many returning customers. It can also fall during a deliberate period of investment that is building future demand.
Neither replaces contribution, the cost of a new customer, repeat purchase or the cash position.
A reporting stack that matches the decision.
For the business: revenue, contribution, cash and stock. For customers: the cost of a new customer, repeat purchase and value by cohort. For marketing as a whole: MER. For each channel: ROAS and the platform's own diagnostics.
Use the measure that fits the decision. If you are deciding whether to increase total marketing investment, MER and contribution matter. If you are moving budget between campaigns, ROAS is still useful.
The better question is not "what is our ROAS?" It is "what did this spend create after margin, customer mix and repeat purchase?"
Bring the report that does not add up.
If the advertising numbers and the business results are telling different stories, share both. That is a good place to start.