> ## Documentation Index
> Fetch the complete documentation index at: https://docs.northbeam.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Validate a channel with an incrementality test

> Measure causal lift, not just credited revenue

**Best for:** confirming whether a channel actually causes revenue before scaling or cutting it.

## Before you start

Attribution measures correlation. If the question is "would these customers have bought anyway?", you need an experiment.

## The steps

<Steps>
  <Step title="Understand what a test measures">
    Test group vs. holdout, and what incremental lift means.
    [Incrementality →](/docs/incrementality)
  </Step>

  <Step title="Pick the channel to test">
    High-spend channels with uncertain attribution (retargeting is the classic case) benefit most.
  </Step>

  <Step title="Read results against your other tools">
    Use lift results to calibrate how you read MTA and MMM for that channel.
    [Mixed Media Modeling →](/docs/mixed-media-modeling)
  </Step>
</Steps>

## What to expect

Tests run for a bounded period and produce a lift estimate you can act on — feeding back into how much you trust each channel's attributed numbers.

## Related

[MTA methodology](/docs/what-is-northbeam-mta-methodology) · [Attribution models](/docs/attribution-models)