ROI (Return on Investment)

1) Meaning

ROI (Return on Investment) is a profitability metric that measures how much return (gain or loss) you get from an investment relative to its cost.

It answers:

“For every $1 spent, how much profit did we earn (or lose)?”

Used in:

• Business (marketing campaigns, product launches, projects)
• Finance (investments, portfolios)
• Supply chain & ops (new systems, process changes)

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2) Formula

$ROI = \frac{\text{Gain from Investment} – \text{Cost of Investment}}{\text{Cost of Investment}} \times 100\%$

Where:

• Gain from Investment = Incremental Revenue or Benefit
• Cost of Investment = Treatment Cost / Campaign Spend / Project Cost

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3) Example

A company runs a promotion campaign:

• Incremental Revenue = $15,000
• Treatment Cost = $10,000

$ROI = \frac{15,000 – 10,000}{10,000} \times 100\% = 50\%$

ROI = 50% → Every $1 spent generated $1.50 back (50¢ profit).

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4) Variations of ROI

• Marketing ROI (MROI): based on incremental revenue from campaigns.
• Return on Ad Spend (ROAS): $ROAS = \frac{\text{Revenue from Ads}}{\text{Cost of Ads}}$
• Risk-adjusted ROI: accounts for uncertainty and variance.
• Time-adjusted ROI: considers time value of money (e.g., NPV, IRR).

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5) In Uplift Modeling Context

• ROI is computed using incremental revenue (uplift effect) vs. treatment cost.
• Avoids wasted spend on Sure Things (buy anyway) and Lost Causes (never buy).
• Ensures targeting focuses on Persuadables where:

$\text{Incremental Benefit} > \text{Treatment Cost}$

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6) Why It Matters

• Business decision-making: Helps compare projects/campaigns.
• Budget allocation: Invest more in high-ROI initiatives.
• Performance accountability: Shows if actions create real value.

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Bottom line:
ROI (Return on Investment) measures the net gain relative to cost, usually expressed as a percentage. It’s the key link between incremental effects (uplift, sales, revenue) and actual business profitability.