ROI in one line
ROI = (revenue − cost) ÷ cost. Spend 10,000 to earn 15,000 and the ROI is 50% — you got back your 10,000 plus half again. It is a ratio, not a percentage of revenue, which is why it can exceed 100%.
ROI versus ROAS versus margin
These three get mixed up constantly. ROI compares profit to investment. ROAS compares revenue to ad spend only. Margin compares profit to revenue. A campaign with 4× ROAS can have negative ROI once product cost and fulfilment are counted — which is exactly how sellers scale themselves into losses.
Using ROI properly
- Include all costs in the denominator: product, ads, fees, shipping, returns
- Compare like windows — a 90-day ROI against a 30-day ROI is meaningless
- Use it for capital decisions (inventory buy, new channel), not daily optimisation
- Pair with payback period: how long until the cash returns
What is a good ecommerce ROI?
For inventory buys, 30–50% per cycle is a common target. For ad spend, judge against contribution margin rather than an abstract percentage, because the same ROI means different things at different volumes.
Frequently Asked Questions
Can ROI be negative?
Yes — if revenue is below cost the ratio goes negative, which is the honest signal to stop.
Is ROI the same as profit margin?
No. ROI is profit ÷ investment; margin is profit ÷ revenue.
Should I annualise ROI?
Only if you compare projects of different durations; otherwise state the period explicitly.
Assumptions & disclaimer
Results are estimates for planning. Fee schedules, tax brackets and deduction limits change; confirm current figures with the marketplace, the IRS or a qualified accountant before making decisions. Nothing here is financial, tax or legal advice.
Privacy & Your Data
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