1. Knowledge base
  2. Experimentation & Validation

Deep Dive: Incrementality vs. Attribution

Incrementality testing and attribution modeling are essential to measure marketing effectiveness. While both methods seek to determine the impact of marketing spend, they serve different purposes and are best used in different contexts.

This guide explains the differences, when to use each approach, and how Cassandra integrates both for better decision-making.


1. Incrementality Testing vs. Attribution Modeling: Key Differences

Factor Incrementality Testing Attribution Modeling
Purpose Measures the true causal impact of marketing activities. Assigns credit to different touchpoints in the customer journey.
Methodology Uses controlled experiments such as GeoLift, Conversion Lift, or A/B testing. Uses statistical models (e.g., first-touch, last-touch, multi-touch attribution) to distribute credit.
Time Frame Requires a testing period with clear pre- and post-experiment phases. Continuously runs and updates based on real-time data.
Best For Understanding if a channel truly drives incremental conversions. Evaluating how different touchpoints contribute to a conversion.
Limitations Can be time-consuming and requires clear test/control groups. Can be biased if not adjusted for multi-channel influences.

2. When to Use Incrementality Testing

Use Cases for Incrementality Testing:

  • Validating Marketing Spend Impact – Helps answer, “Would sales still happen without this campaign?”

  • Testing New Channels – Before committing a large budget, test whether a new platform drives additional conversions.

  • Geo-Experiments – Hold out specific regions to measure the lift from a marketing campaign.

  • Reducing Cannibalization – Understand whether one channel is taking credit for conversions that would have happened anyway.

Challenges of Incrementality Testing:

  • Requires careful experiment design and test/control selection.

  • May not be feasible for all channels (e.g., brand awareness campaigns).

  • Can take weeks to run and analyze effectively.


3. When to Use Attribution Modeling

Use Cases for Attribution Modeling:

  • Optimizing Real-Time Spend – Attribution provides ongoing insights into how different channels contribute to conversions.

  • Multi-Touch Analysis – Helps distribute credit among various marketing interactions.

  • Evaluating Path to Conversion – Tracks user journeys across touchpoints (e.g., paid search → organic search → conversion).

Challenges of Attribution Modeling:

  • Can over-credit certain channels if not calibrated correctly.

  • Struggles with cross-device tracking and walled-garden platforms (e.g., Meta, Google).

  • Does not account for organic demand or cannibalization effects.


4. How Cassandra Integrates Both Approaches

Combining Incrementality and Attribution for Better Decisions

  • Calibrated Attribution – Cassandra uses incrementality insights to adjust attribution models, reducing bias in touchpoint weighting.

  • MMM + Incrementality Tests – Marketing Mix Modeling (MMM) is enhanced with controlled experiments to fine-tune budget allocation.

  • Cross-Validation – Attribution provides continuous data, while incrementality tests serve as a validation layer.

Example Integration Workflow:

  1. Use attribution modeling to assess the impact of each marketing channel daily.

  2. Run incrementality tests quarterly on key channels to validate or adjust assumptions.

  3. Calibrate MMM models by incorporating learnings from both attribution and experiment results.

  4. Apply findings to budget allocation using Cassandra’s Budget Allocator for optimized spend decisions.


5. Summary & Next Steps

  • Incrementality testing helps measure true lift, while attribution modeling distributes credit across channels.

  • Use incrementality tests periodically to validate and refine attribution models.

  • Leverage Cassandra’s combined approach to get the most accurate marketing impact measurement.

  • Regularly review and calibrate models to adjust for changing consumer behavior and marketing dynamics.