ROI (Return on Investment)

ROI (Return on Investment) measures how much an investment returned relative to what it cost.

The formula

$$ROI = \frac{gain - investment}{investment} \times 100$$

You invested R$ 10,000 and got R$ 15,000 in return: an ROI of 50%. The net gain was R$ 5,000 on R$ 10,000.

⚠️ Common mistake: saying that case has "an ROI of 1.5." That is the multiple of the return, not the ROI. Since the formula subtracts the investment, an ROI of 100% means doubling the money, not breaking even.

ROI and ROAS are not the same thing

• ROAS (Return on Ad Spend) — revenue divided by media spend. Only looks at the ad.
• ROI — considers all costs: media, team, tools, production.

A campaign with an excellent ROAS can have a negative ROI once you add the salary of whoever ran it. That is why marketing tends to report ROAS and finance insists on ROI.

What almost always gets left out of the calculation

• Team cost — the biggest and the most forgotten.
• Tools and licenses.
• Time to return. A 50% ROI in one month and in two years are different things; with no stated timeframe, the number is not comparable.
• Opportunity cost — the same money spent elsewhere.

In support and sales

Calculating the ROI of a CRM or of support requires separating what is effect from what is coincidence. The honest path is measuring one isolated variable — first-response time, conversion rate per pipeline stage, churn — before and after, in the same period of the year. Attributing all growth to the new tool is the kind of math that does not survive a finance team's question.