ROI: definition, formula and calculation in marketing

A positive ROI indicates a profitable investment; a negative ROI indicates a loss. A ROI of 100% means you have doubled your stake.

Unlike ROAS, which simply divides gross revenue by advertising spend, ROI incorporates all costs (production, salaries, tools, platform fees) and is generally calculated on gross margin, not on revenue.

In digital marketing, calculating ROI is often complicated by the difficulty of accurately attributing revenue to a specific action — this is the multi-touch attribution problem.

ROI can be calculated by channel:

• SEO: deferred but high ROI over the long term (12–36 months)
• SEA: immediate but one-off ROI, dependent on budget
• Email: average ROI of 3,600–4,200% according to industry studies

ROI is the strategic KPI par excellence because it transcends disciplines and allows investments of very different natures to be compared on the same scale.

Without ROI calculation, budget decisions rely on intuition rather than data. ROI is also the decisive argument for obtaining additional budgets: demonstrating a 300% ROI on a past action is the best argument to convince a CFO to increase the marketing budget.

• A ROI calculated on margin (not revenue) gives a realistic view of profitability
• SEO ROI takes time but is cumulative: each piece of content continues to generate traffic
• Email ROI is structurally high thanks to low sending costs

1. 1Precisely measure all costs associated with each action (don't forget team time).
2. 2Identify high-ROI actions and replicate them at greater scale.
3. 3Eliminate or reduce investments with negative or insufficient ROI.
4. 4Optimise the conversion rate to increase revenue without increasing costs.
5. 5Prioritise channels with cumulative effect (SEO, content, email) whose ROI improves over time.
6. 6Set up rigorous attribution tracking to avoid double-counting the same revenue.