What is ROAS?
ROAS, or return on ad spend, measures how much revenue a campaign generates for each dollar spent on ads. It is calculated by dividing attributed revenue by ad spend. A ROAS of 4, often written as 4:1 or 400%, means every $1 of ad spend brought in $4 of revenue.
It is one of the main performance metrics for ecommerce and retail campaigns.
How is ROAS calculated?
The formula is simple:
ROAS = revenue attributed to ads / ad spend
For example, if you spend $2,000 on a campaign and it drives $9,000 in attributed sales, ROAS = 9,000 / 2,000 = 4.5. That can be shown as 4.5, 4.5:1 or 450%. The same formula works per channel, campaign or audience, so you can see which part of the plan is carrying results.
Two choices shape the number:
What counts as spend: media cost only, or media plus platform, data and agency fees. Including all costs gives a more honest view.
What counts as revenue: this depends on the attribution model and window. A 14-day post-click window credits different sales than a 1-day post-view window, so ROAS should only be compared across campaigns that use the same settings.
To find break-even ROAS, divide 1 by your profit margin. With a 25% margin, break-even ROAS is 1 / 0.25 = 4. Below 4, the campaign loses money on the first sale.
Why ROAS matters
ROAS ties ad spend directly to revenue, which makes it easy to compare campaigns, channels, audiences and creatives. Many ad platforms can also optimize bids toward a ROAS goal when they receive conversion values.
A good ROAS depends on the business. A high-margin product can be profitable at a low ROAS, while a low-margin retailer may need a much higher one, which is why your break-even ROAS is a better benchmark than any industry average.
ROAS has blind spots, though:
It shows attributed sales, not proof the ads caused them. Incrementality testing answers that question.
It favors bottom-funnel tactics like retargeting, which often claim sales that would have happened anyway.
It ignores customer lifetime value, so a low-ROAS campaign that wins loyal customers can look worse than it is.
ROAS vs ROI
ROAS measures revenue against ad spend only. ROI, or return on investment, measures profit against total investment, including product costs, fees and overhead. A campaign can have a strong ROAS and still produce a negative ROI if margins are thin. ROAS is useful for optimizing campaigns day to day, ROI for judging whether advertising makes the business money. Use ROAS to steer and ROI to decide. A related metric, CPA, measures cost per conversion rather than revenue.
ROAS with AdGeeks
ROAS is a core metric in retail media, especially on Amazon DSP, where ads can be measured against sales of products sold on Amazon, and on DV360 with conversion tracking in place. AdGeeks traders agree attribution settings with you first, optimize toward your ROAS target and report it alongside new-to-brand and incrementality signals where available.
