Return on Investment (ROI) measures how much incremental value each marketing dollar generates. Decomposition provides the contribution data needed to calculate accurate marketing ROI.
Purpose: Calculate ROI for each channel and group to optimize budget allocation and demonstrate marketing effectiveness.
Basic ROI Formula
Standard Calculation:
ROI = (Incremental Contribution / Marketing Spend) - 1
Sum the contribution column for each channel
Example from Variable Decomposition sheet:
TV_Spend column: sum all values = $500,000
Digital_Spend column: sum all values = $400,000
Radio_Spend column: sum all values = $200,000
Sum actual spend for same time periods
TV total spend: $200,000
Digital total spend: $150,000
Radio total spend: $100,000
TV ROI = ($500,000 / $200,000) - 1 = 1.5 = 150%
Digital ROI = ($400,000 / $150,000) - 1 = 1.67 = 167%
Radio ROI = ($200,000 / $100,000) - 1 = 1.0 = 100%
Media Group Includes: TV, Digital, Radio, Print
Total Media Contribution: $1,150,000
Total Media Spend: $500,000
Media ROI = ($1,150,000 / $500,000) - 1 = 130%
January TV Contribution: $45,000
January TV Spend: $20,000
January ROI: 125%
February TV Contribution: $50,000
February TV Spend: $20,000
February ROI: 150%
Insight: ROI improving month-over-month
Black Friday Campaign (3 weeks):
Campaign weeks TV contribution: $150,000
Baseline (without campaign): $30,000
Incremental lift: $120,000
Campaign spend: $80,000
Campaign ROI = ($120,000 / $80,000) - 1 = 50%
Compare two spend levels:
At $100K spend: $200K contribution (100% ROI)
At $150K spend: $270K contribution (80% ROI)
Marginal contribution of extra $50K: $70K
Marginal ROI: ($70K / $50K) - 1 = 40%
Customer Acquisition Cost: $100
Immediate Revenue from Customer: $50
First Purchase ROI: -50% (looks bad)
But...
Lifetime Value: $500
True ROI = ($500 / $100) - 1 = 400%
WRONG - Total ROI:
Total Sales during TV Campaign: $1M
TV Spend: $200K
ROI = 400% (INCORRECT - includes baseline sales)
CORRECT - Incremental ROI:
Incremental Sales from TV (from decomposition): $300K
TV Spend: $200K
ROI = 50% (CORRECT - only TV's contribution)
Digital ROI: 200%
Action: Test increasing Digital budget by 20%
Monitor: Does ROI remain above 150%?
Print ROI: 20%
Action: Cut Print budget by 50% or eliminate
Reallocate: Move budget to higher ROI channels
Current: $100K spend at 150% ROI
Test: $120K spend
If ROI stays >130%: Continue increasing
If ROI drops <100%: Reduce back
Scenario A: All budget in highest ROI channel (Digital 200%)
Risk: Saturation, diminishing returns, lack of diversification
Scenario B: Balanced across channels
- Digital (200% ROI): 50% of budget
- TV (100% ROI): 30% of budget
- Radio (80% ROI): 20% of budget
Benefit: Diversification, sustainable long-term
❌ ROI = Total Sales / Spend
✓ ROI = Incremental Contribution from Decomposition / Spend
❌ Q1 contribution / Q2 spend
✓ Same time periods for both
Consider adstock: This month's spend may impact next month
Decomposition captures this in contributions
If using Min adjustment, calculate ROI on incremental only
Document adjustment in ROI reporting
TV (brand building) vs. Search (direct response)
Different time horizons, different ROI expectations
Channel: Digital Search
Performance Period: Jan - Dec 2024
Metrics:
- Total Contribution: $400,000
- Total Spend: $150,000
- ROI: 167%
- Return Multiple: 2.67x
Comparison:
- vs. Last Year: +15% (was 145%)
- vs. Industry Benchmark: Above average (150-300% range)
- Rank: #1 in portfolio
Trend:
Q1: 150% → Q2: 165% → Q3: 175% → Q4: 180%
Improving over time
Recommendation:
Increase investment by $50K
Expected additional contribution: $100K
Projected ROI: 150%+