ROI
読み方：R-O-I
Return on Investment. A measure of the profitability of an investment. ROI = (Profit from Investment - Cost of Investment) ÷ Cost of Investment × 100. Used to compare the efficiency of different marketing investments and business decisions.
What is ROI
ROI (Return on Investment) measures how much profit you generated relative to what you spent. It's the universal language of investment efficiency.
ROI Formula
ROI (%) = (Net Profit ÷ Investment Cost) × 100
Where Net Profit = Revenue - Investment Cost
Example: Spend $100,000 on SEO; generate $400,000 in attributed revenue; gross margin 50%
Net Profit = ($400,000 × 0.5) - $100,000 = $100,000
ROI = ($100,000 ÷ $100,000) × 100 = 100%
ROI vs. ROAS
- • ROAS uses revenue (not profit) and only counts ad spend
- • ROI uses profit and can include all costs (staff, tools, agencies)
ROAS looks better than ROI by design—which is why both should be tracked.
Attribution Challenges
Not all marketing impact is directly attributable. Brand awareness campaigns influence purchases made weeks later via other channels. Last-click attribution undervalues top-of-funnel investment.
Long-Term ROI
SEO and content marketing often show negative short-term ROI (investment before significant returns). Evaluating at 6 or 12 months captures the actual return more accurately.