Incrementality Testing
Deliverables
The Headline Result
When your test concludes, Maxma answers the question you ran it for: how much did the advertising actually drive? The headline result shows:
- Incremental conversions — the total orders, signups, or other conversions the ads caused, beyond what would have happened anyway
- Cost per incremental conversion — spend divided by the conversions the ads actually caused: the true cost of growth from this channel, ready to compare against your target CPA
- Percent lift — the incremental impact relative to the baseline, so you can compare results across tests and channels
- Confidence range — the band the true impact falls within; a tight range means a precise measurement
- Statistical significance — whether the measured lift is a real effect or within the range of normal noise
The baseline is what your test regions would have done without the advertising, projected from how the control regions actually performed. That comparison is what makes the result incremental — not correlated, not modeled from clicks, but measured against a true holdout.
What Happened vs. What Would Have Happened
Results include a time-series view of the test regions against the control baseline, and it's the most intuitive way to see what the campaigns drove. By design, test and control regions are selected to move together — and through the pre-test period, the two lines do exactly that, visible proof the comparison is fair. Then the campaigns launch, and the lines separate: the test regions pull ahead while control carries on as usual. That gap is lift driven by your campaigns — conversions that would not have happened otherwise.
No Cookies, Devices, or UTMs Required
This measurement doesn't rely on cookie, device, or UTM tracking by design — it's based purely on regional outcomes. In practice, we often find that channels where people see ads but rarely click through — the ones click-based tracking struggles to credit — still show clear lift in a geo test.
Lift Over Time
Alongside this view, Maxma tracks the cumulative lift as the test progresses — and keeps tracking it after the test ends.
That matters because of lingering effects: advertising impact doesn't stop the day the campaign does. It's common to see incremental conversions continue to accumulate in the weeks after the test concludes — impact that click-based measurement misses entirely, and that Maxma captures by continuing to evaluate through the cooldown period.
Results for Every Metric
Multiple Conversions, One Test
A single experiment can measure multiple conversion metrics at once — funnel stages like visits, signups, and purchases, or segments like new vs. returning customers. Every metric gets the same full set of results: headline lift, confidence range, and the over-time views.
You see not just whether the advertising worked, but where in the funnel and for whom. Keep in mind the experiment is powered for your primary metric, so secondary metrics may show wider confidence ranges.
From Results to Decisions
A significant positive lift is a green light to scale the channel with confidence. A flat result is just as valuable — it tells you where spend isn't working before you scale it. And when a result is inconclusive, the AI expert helps you interpret why and design the follow-up test, so every experiment moves your budget toward what provably works.