Incrementality
The true lift in conversions directly caused by a marketing activity.
1 min readLast updated Apr 2026
Quick Reference
CategoryMarketing & Paid Advertising
Related Terms2
The true lift in conversions directly caused by a marketing activity.
Why It Matters
Incrementality answers the most important question in marketing: 'Would this conversion have happened anyway without this ad?' Unlike attribution (which shows correlation), incrementality proves causation. Understanding this prevents over-investing in channels that just take credit for organic demand.
Practical Example
Scenario
A brand's Meta branded retargeting shows 10x ROAS. They run a holdout test excluding 20% of their retargeting audience from ads.
Calculation
Control group conversion rate: 4.8%. Exposed group: 5.2%. Incremental lift: (5.2-4.8)/4.8 = 8.3%Result
Only 8.3% of 'retargeting conversions' were actually caused by the ads. True incremental ROAS is 0.8x, not 10x.
Pro Tips
- 1Test incrementality on your highest-spend channels first—that's where waste would hurt most
- 2Run incrementality tests quarterly as channel effectiveness changes over time
- 3Don't just test channels—test audiences too. High-intent retargeting often has low incrementality
Common Mistakes to Avoid
Assuming high ROAS means high incrementality—they're completely different concepts
Running incrementality tests without sufficient sample size, leading to inconclusive results