ROAS and ROI are often confused. Here's what each metric actually measures, when to use which one, and how to set targets that make sense for your business.
The Core Difference
Both metrics measure return on investment, but they measure different things.
ROAS (Return on Ad Spend) compares revenue from ads to the cost of those ads: ROAS = Revenue ÷ Ad Spend. If you spent $1,000 and generated $4,000 in sales, your ROAS is 4x (or 400%).
ROI (Return on Investment) compares net profit to total investment: ROI = (Net Profit ÷ Investment) × 100. Net profit means revenue minus all costs — product, fulfilment, overhead, taxes, and yes, ad spend.
ROAS is a fast tool for comparing campaigns. ROI is the real measure of whether your business is profitable.
Why ROAS Can Mislead You
A ROAS of 5x sounds great. But if your product margin is 18%, a 5x ROAS still means you’re losing money on every sale once you account for cost of goods.
This is the most common trap in e-commerce advertising. A business optimises toward a high ROAS without calculating the margin threshold first. The ads “perform well” while the business bleeds cash.
Your minimum viable ROAS is 1 ÷ gross margin. If your margin is 30%, you need a ROAS of at least 3.3 just to break even on the ad spend. Anything below that is subsidising customers.
When to Use ROAS
ROAS is the right tool for campaign-level decisions: which campaigns to scale, which to pause, where to shift budget within your ad account. It’s fast to calculate and easy to compare across campaigns.
Use ROAS to answer: Is this campaign worth its budget compared to others?
When to Use ROI
ROI is the right tool for business-level decisions: whether advertising as a channel is working, whether to increase the overall marketing budget, how paid ads compare to other growth investments.
Use ROI to answer: Is advertising making this business more profitable?
Setting Targets
Start from your margin, not from industry benchmarks. Industry “good ROAS” figures are meaningless without knowing the margin they assume.
Calculate your breakeven ROAS: 1 ÷ gross margin percentage. Set your target ROAS 20–40% above breakeven to leave room for profit. For ROI, define what annualised return you need from your marketing budget to justify it over other uses of capital.
In Short
- ROAS measures revenue vs ad spend; ROI measures net profit vs total investment
- A high ROAS can still mean losing money if margins are thin
- ROAS is for campaign optimisation; ROI is for business-level decisions
- Always calculate your breakeven ROAS before setting targets
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