What ROAS actually measures
Return on ad spend compares the value attributed to advertising with the amount spent on those ads. If a campaign records $4,000 in conversion value from $1,000 of ad spend, its reported ROAS is 4×, or 400%.
That describes a relationship between two numbers. It does not tell you how much money remains after producing, delivering, and supporting the orders. It also depends on what you send into the platform as conversion value. Revenue, estimated lead value, and gross profit are different inputs.
Start with one question: What does “conversion value” represent in this account? Before comparing two campaigns, make sure the answer is consistent.
Put the costs back in the picture
Here is a simplified, hypothetical example. Two stores each report $4,000 in revenue from $1,000 in advertising. Both show 4× ROAS. Store A has $1,600 in product, fulfilment, and other variable costs. Store B has $2,800. After those costs and advertising, Store A retains $1,400; Store B retains $200. Neither figure includes fixed overhead.
The same advertising return can support very different businesses. Discounts, delivery subsidies, returns, and payment fees can change the picture further. This is why a competitor’s target is a poor substitute for your own cost model.
- Define value: Confirm whether your reported amount includes tax, shipping, or estimated values.
- Reconcile orders: Compare advertising reports with your store or CRM, allowing for different attribution rules and reporting dates.
- Check the mix: A campaign selling mostly low-margin items can look different once costs are included.
Use the number to make a better decision
Build a simple review that puts ad spend, recorded value, customer quality, and contribution after variable costs together. Keep the date range and definitions consistent. If purchases arrive days after the first click, give the reporting period time to mature before making a judgement.
Google’s Target ROAS bidding works toward conversion value relative to cost. The target is an optimisation objective, not a guaranteed return on every purchase. The quality of the values you report therefore matters alongside the target you choose.
A useful next step is to write down what would make additional spend worthwhile for your business. That might involve margin, lead qualification, repeat purchase behaviour, or cash constraints. ROAS can help answer the question, but it should not be the only evidence in the room.
Platform reference: Google Ads Help — About Target ROAS bidding. The store comparison above is an illustrative example, not a client result.