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Content/Frameworks/Measurement

Incrementality over attribution.

Attribution is what the platform credits itself. Incrementality is what actually happened in the business. Geo-lift and holdout tests give you the upper bound on causal claims. Plug your test results in to see how much your platform was overstating credit.

⌘ Framework·Interactive· NMaintained by Nathan Perdriau
Try it on your test results

Calculate incremental lift.

Drop in your geo-lift test data. The tool calculates incremental conversions, true CAC, and the percentage by which platform attribution was overstating credit.

Your test inputs

#
// Conversions in geographies WITHOUT the spend, normalised to test market size
#
// Conversions in geographies WITH the spend, same period
A$
// Total paid media spend allocated to test markets in the period
#
// What Meta/Google credited itself for during the test

The causal read

// Incremental conversions
200
Test minus control
// True CAC
A$ 150
Spend ÷ incremental
Platform overstated by 40%

Platform is overstating its causal contribution. Scale decisions made against the platform-credited number would be over-investing. Use the true CAC as the upper bound for spend decisions.

// Incremental = Test − Control · True CAC = Spend ÷ Incremental · Inflation = (Platform-credited − Incremental) ÷ Incremental

The platform's incentive is to credit itself generously. The business's incentive is to know what actually moved.

A geo-holdout test answers the question attribution cannot. Run paid media in one set of geographies (test markets), pause it in another (control markets). The difference in conversions across the test period is the incremental contribution of the spend. Whatever the platform was crediting itself, this is the actual upper bound.

What the gap usually looks like.

Across the test programs we run, platform-reported conversions typically overstate incremental contribution by 25-60%. The exact number varies by category, brand awareness, and spend tier, but the direction is consistent. If you do not test, you are scaling spend off a credited number that has a known inflation problem.

The three measurements to keep.

  • Incremental conversions. Test market actuals minus what the control would predict.
  • True CAC. Ad spend divided by incremental conversions. The number to scale against.
  • Attribution inflation. The percentage the platform was overstating before the test.
If this matches how you think

Run the same diagnostic on your own account.

We design and run geo-lift tests sized for statistical confidence, then walk you through how much attribution your account is currently overstating. Free strategy session and audit. No obligation.

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