What is ROI (return on investment)
Also known as: Return on Investment
ROI (return on investment) is the percentage that shows how much an investment earned beyond what it cost. You subtract the cost from the gain and divide the result by the cost. A 100% ROI means the investment came back in full and generated the same amount again in profit; a negative ROI means a loss.
ROI = (gain − cost of investment) ÷ cost of investment × 100
In marketing, the "gain" should be the profit from the sales attributed to the campaign, not revenue. Google Ads Help itself defines ROI as the ratio between the profit earned and what was spent on ads.
A store invested $5,000 in a Google Ads campaign in one month. Sales from the campaign totaled $25,000 in revenue. After the cost of goods sold, shipping and fees, $9,000 of gross profit was left.
ROI = ($9,000 − $5,000) ÷ $5,000 × 100 = 80%.
Had the store used revenue in the math, the result would be ($25,000 − $5,000) ÷ $5,000 = 400%, five times the real return. That confusion is the most common reason a campaign looks great and leaves no money in the bank.
ROI and ROAS are not the same thing
Both compare results with investment, but they measure different things. ROAS divides the revenue generated by ads by what was spent on them. ROI uses profit, and can include costs beyond media.
In practice, ROAS is the media buyer's daily number, because the ad platform sees revenue. ROI is the business decision number, because only it tells you whether money was left over.
| ROI | ROAS | |
|---|---|---|
| What it compares | Profit with total cost | Revenue with media spend |
| How it is shown | Percentage (80%) | Multiplier (5x) or percentage (500%) |
| Where it is used | Deciding to invest or cut | Optimizing campaigns and bids |
| Needs margin? | Yes | No |
What goes into the cost of the investment
ROI is only as honest as the list of costs. For a campaign, besides media, the list can include creative production, the agency, tools and the team's time spent on it. Leaving costs out raises ROI on paper and lowers it in the bank.
The same goes for timing: if a campaign drives sales that only land the following month, measuring ROI only in the month of the spend underestimates the return. Decide on the measurement window up front.
How to read marketing ROI
- Negative ROI: the action cost more than the profit it brought in the measured period.
- Zero ROI: break-even. The investment came back but generated no extra profit.
- Positive ROI: profit beyond the investment. Higher is better, as long as the volume makes sense for the business.
- High ROI with low volume: may signal room to invest more before returns start to fall.
When ROI misleads
Brand, content and SEO work often shows low ROI in the short term and high ROI in the long term, because the effect compounds. Measuring everything with the same 30-day window always favors direct-response ads and penalizes what builds demand.
Attribution is the other caveat: if a customer saw an ad, read an article and came back through Google, the sale may be credited to a single channel. Each channel's ROI depends on the attribution model you choose.
How to improve ROI
- Cut what does not convert, looking campaign by campaign rather than at the account average.
- Improve the page's conversion rate, which raises profit without raising cost.
- Prioritize higher-margin products and services in campaigns.
- Measure real profit, with each product's margin, rather than an estimated average margin.
Frequently asked questions
How do you calculate ROI?
Subtract the cost of the investment from the gain, divide the result by the cost and multiply by 100. In marketing, use the profit generated by the sales, not the revenue.
What is the difference between ROI and ROAS?
ROAS divides ad revenue by media spend. ROI uses profit and can include other costs. ROAS optimizes campaigns; ROI tells you whether money was left over.
What is a good marketing ROI?
Any positive ROI means the action returned more than it cost. The ideal value depends on the business's margin, sales cycle and the volume it needs.
Can ROI be negative?
Yes. A negative ROI means the profit generated in the period was lower than the cost of the investment, so the action lost money.
How do you measure the ROI of SEO and content?
With a longer measurement window, measured in months, and attribution that credits the first touch. SEO and content build results over time and rarely pay back in the first month.
Related terms
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- CPACPA in marketing is cost per acquisition: how much a business spends on ads to generate each conversion...
Rodrigo Fávaro
Founder of ROO3, a marketing and technology agency in São José do Rio Preto, Brazil. Builds AI products running in production (Tobia, gerar.app, Pense Mercado) and maintains the AI Benchmark, a public ranking of AI models.
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