ROI in marketing isn’t complicated mathematically—but the real difficulty is defining what counts as “return” and what costs you include. I’ll break it down both formula-wise and practically.

🔹 2. What counts as “Return”?

This is where most people go wrong.

✅ Best case (ideal):

• Direct revenue from campaign conversions

Example:

• Campaign generated €50,000 in sales

⚠️ Sometimes more complex:

Depending on your setup, you might use:

• Attributed revenue (from tracking tools)
• Incremental revenue (what wouldn’t have happened without the campaign)
• Customer Lifetime Value (CLV) (if campaign brings new customers)

👉 Example with CLV:

• 100 new customers × €200 lifetime value = €20,000 return

🔹 3. What counts as “Investment”?

You need the full cost, not just ad spend.

Include:

• Ad spend (Google, Meta, etc.)
• Creative production (videos, design)
• Agency or team costs
• Tools/software (if significant)

👉 Example:

• Ads: €10,000
• Creative: €2,000
• Total cost: €12,000

🔹 6. The Real Logic (What you’re actually measuring)

ROI answers:

“Was this campaign worth the money?”

So you’re comparing:

• What you gained
  vs
• What you spent to gain it

🔹 7. Advanced Thinking (what makes you stand out)

Good marketers don’t just calculate ROI — they question it:

🔸 Attribution problem

• Was the sale really from the campaign?
• Or would it happen anyway?

🔸 Time lag

• Campaign today → revenue next month

🔸 Brand campaigns

• Awareness doesn’t convert immediately

👉 In those cases, ROI is:

• harder to measure
• sometimes underestimated

🔹 8. Clean way to explain it in an interview

If you had to say it simply:

“To calculate ROI, I compare the revenue generated by the campaign to its total cost. I subtract the investment from the return to get the net profit, divide by the cost, and express it as a percentage. I also ensure that the revenue is properly attributed and, when relevant, I consider customer lifetime value to get a more accurate picture of long-term impact.”

🔥 Final takeaway

ROI is not just a formula—it’s a decision tool.

👉 A “good” ROI means:

• You created more value than you spent

👉 A “bad” ROI means:

• Your strategy, targeting, or channels need fixing