Incremental ROAS (Incremental Return on Ad Spend) measures the additional revenue generated specifically as a result of advertising, beyond what would have occurred without the ads. Unlike standard ROAS, which evaluates total revenue attributed to advertising, Incremental ROAS focuses on the true lift created by the campaign.
This metric helps marketers determine whether advertising is genuinely driving new revenue or simply capturing conversions that would have happened anyway.
How Incremental ROAS Works
Incremental ROAS compares the incremental revenue generated by ads to the cost of the advertising investment.
Formula:
Incremental ROAS = Incremental Revenue ÷ Ad Spend
Incremental revenue represents the additional sales caused directly by advertising exposure, often measured through experiments such as holdout groups or incrementality tests.
For example:
- Ad spend: $10,000
- Total attributed revenue: $40,000
- Revenue that would have happened anyway: $20,000
Incremental revenue = $20,000
Incremental ROAS = $20,000 ÷ $10,000 = 2.0
This means every dollar spent generated two dollars in additional revenue.
Why Incremental ROAS Matters
- Measures True Advertising Impact
Distinguishes between revenue caused by ads and revenue that would have occurred organically. - Improves Budget Allocation
Helps marketers invest more in campaigns that create genuine growth. - Reduces Over-Attribution
Prevents channels from receiving credit for conversions they did not actually influence. - Supports Strategic Scaling
Helps determine whether increasing advertising spend will produce real business growth.
Incremental ROAS vs. Standard ROAS
- Standard ROAS: Total revenue attributed to advertising divided by ad spend.
- Incremental ROAS: Only the additional revenue generated because of the advertising.
Standard ROAS can sometimes overestimate performance, while Incremental ROAS provides a more realistic measure of marketing effectiveness.
How Incrementality Is Measured
Incremental ROAS is often determined through methods such as:
- Holdout group testing
- Geo experiments
- Conversion lift studies
- A/B testing between exposed and unexposed audiences
These approaches help isolate the true impact of advertising campaigns.
Summary
Incremental ROAS measures the additional revenue generated directly by advertising compared to the cost of the campaign. By focusing on the true lift created by ads rather than total attributed revenue, it provides a more accurate view of marketing effectiveness and helps businesses make better budget and scaling decisions.