A campaign reports a 5x return on ad spend. That sounds promising: five dollars in attributed revenue for each dollar spent on advertising.
But the revenue still has to pay for the product, fulfilment, fees, returns and the advertising itself. The business also has ongoing costs beyond those orders.
When comparing ROAS vs. profit, the missing question is how much money remains after the relevant costs. A high revenue ROAS can be useful, but it is only one part of that calculation.
Understand what your reported ROAS measures
For a campaign reporting revenue-based ROAS:
ROAS = revenue attributed to advertising ÷ advertising spend.
If a campaign attributes $5,000 in revenue to $1,000 of ad spend, its revenue ROAS is 5x, or 500%.
That calculation does not deduct the costs of supplying those orders. It also depends on what revenue is recorded and how purchases are attributed.
Google’s Target ROAS bidding uses the conversion values advertisers report.[1] If those values represent revenue, the system is working toward a revenue-based value-to-cost target. It does not automatically become a calculation of net business profit.
If you send a different value, such as an estimate of contribution, interpret the reported ratio on that basis. A ratio based on profit values and one based on sales revenue are different measures.
Compare campaigns using the margins behind the sales
Consider two hypothetical eCommerce campaigns. Both spend $1,000 on ads, but they sell product mixes with different margins.
For this example, contribution margin before advertising means net revenue remaining after variable costs such as products, fulfilment, transaction fees and expected returns. Advertising has not yet been deducted.
| Metric | Campaign A | Campaign B |
|---|---|---|
| Advertising spend | $1,000 | $1,000 |
| Attributed net revenue | $5,000 | $4,000 |
| Revenue ROAS | 5x | 4x |
| Contribution margin before advertising | 20% | 40% |
| Contribution before advertising | $1,000 | $1,600 |
| Contribution after advertising | $0 | $600 |
Campaign A has the higher revenue ROAS, but all its contribution is used by the ad spend. Campaign B leaves $600 after advertising.
These are hypothetical calculations, not client results. They illustrate why the product mix and cost structure affect the value of a sale.
The $600 is contribution after advertising, not net profit. Fixed overhead and any other costs excluded from the margin still need to be covered.
Calculate a useful break-even reference
Under the assumptions used above:
Break-even revenue ROAS = 1 ÷ contribution margin before advertising.
Use the margin as a decimal. A 40% margin is 0.40, giving a break-even revenue ROAS of 2.5x. A 20% margin is 0.20, giving 5x.
This reference covers the variable costs included in the margin and the advertising spend. It is not a complete company-profit target.
Build management fees, creative production, software, fixed overhead and the desired profit into the wider budget assessment. If a cost changes with orders or spend, account for it consistently rather than treating it as fixed by default.
One store-wide average can also hide important differences. Review margins by product or category where those differences affect advertising decisions.
Check the value being recorded
Reliable interpretation starts with reliable data.
Compare purchase values in advertising reports with the underlying orders. Investigate duplicate purchase events, inconsistent currencies, discounts and the handling of cancellations or refunds.
Use a consistent revenue basis. A calculation using gross sales including tax and another using net revenue after returns will not describe the same result.
Review the reporting period and attribution settings too. Customers may purchase after the initial ad interaction, so recent data can still be incomplete.
If Google Ads and Meta Ads both report a purchase, adding their attributed revenue without checking the underlying orders can double-count that sale. Reconcile the platform views with business records rather than assuming they are separate groups of orders.
A conversion tracking review can help establish what is being recorded and where the reports need additional context.
Separate new customers from returning demand
The same revenue ROAS can represent different customer outcomes.
A campaign may attract first-time buyers, repeat customers or a mixture. Those groups can have different acquisition costs, repeat-purchase patterns and margins.
Where your records support it, review new-customer acquisition alongside total attributed revenue. Also review which products those customers buy and whether discounts or shipping incentives change the economics.
An easy purchase from an existing customer and a purchase from someone discovering the brand for the first time should not automatically receive the same strategic interpretation.
This does not make returning customers unimportant. It gives you a clearer view of what each campaign is contributing and what further testing should investigate.
Assess repeat purchases using actual evidence
Some businesses accept a lower first-order return because customers make profitable repeat purchases.
That can be a reasonable model when the repeat behaviour and costs are supported by reliable customer records.
Review customer groups acquired during comparable periods. Examine their subsequent purchases, returns, discounts and the costs of fulfilling and marketing those orders.
Keep observed outcomes separate from forecasts. A future repeat purchase should not be treated as money already earned, and delayed revenue still affects the cash needed to sustain advertising.
Where repeat-purchase evidence is weak, base the initial assessment on what the business can establish today.
Connect optimisation with the value you want
Google’s conversion-value guidance allows advertisers to choose values aligned with their business objectives, including transaction-specific values.[2] The useful principle is to be clear about what you are asking the campaign to maximise.
If you use revenue values, review the resulting product mix and margins separately. If you use another value model, document the assumptions and keep a revenue view available for comparison.
A ROAS target also needs context. A very restrictive target can limit traffic and conversion value; a less restrictive target may bring additional orders with different economics.
When considering more budget, ask what the additional spend is expected to produce. Review additional revenue, variable costs and contribution, rather than relying only on the average return from the current budget.
Use a wider set of measures
For an eCommerce advertising review, useful measures include revenue ROAS, net revenue, customer acquisition cost, contribution after advertising and total marketing costs.
They answer different questions. Together, they help you distinguish a campaign with an attractive reported ratio from one supporting a sustainable business result.
At TerryKX Media, I manage eCommerce PPC campaigns with attention to tracking, product performance and acquisition costs. The analysis uses the business information available, with assumptions made clear where cost or customer data is incomplete.
Discuss your eCommerce advertising performance and share your current campaign results, main products and the cost information you use to judge success.
Sources
[1] Google Ads Help, About Target ROAS bidding.
[2] Google Ads Help, Conversion Values Best Practices.