Best incrementality testing tools in 2026: five platforms, the free options, and who each suits
Five incrementality testing platforms whose sites describe geo experiments: Haus for experiments first, Measured for enterprise brands, Sellforte for retail and ecommerce, SegmentStream for a high-touch partner, and Cassandra for tests that move budgets and ads. GeoLift, CausalImpact and Meridian GeoX are free options.
We are Cassandra, one of the five, and we wrote this page. The order is not a verdict.
How these were chosen
- The rule: platforms whose own pages describe geo experiments that guide spend.
- The pick: four, plus us. A choice, not a measurement.
Cassandra
An AI marketing brain for growth teams that moves budgets and ads within the rules the team sets.
A Bayesian marketing mix model checked by live geo experiments. Every move is checked against its forecast.
Start for free with your website and data, or book a demo. Paid plans scale with yearly ad spend.
Best for ecommerce brands, nonprofits and agencies. Customers include Gina Tricot, Velasca and charity: water.
A channel needs enough spend history and variation to read. Geo experiments need regional structure. Tests take a few weeks.
Measured
Their own words: the AI-powered marketing effectiveness platform trusted by enterprise brands.
Describes automated geo and audience split experiments, and a causal media mix model calibrated with incrementality tests.
Pricing is quoted on request: the site invites you to book a demo.
Best for enterprise brands wanting experiments and a test-calibrated model from one vendor.
Focused on enterprise: its site says it is built for enterprise and for complex businesses.
Sellforte
Their own words: the Measurement & Optimization OS for Retail and Ecommerce.
Describes geo lift experiments with Bayesian synthetic control, and incremental ROAS by campaign and ad set.
Its Incrementality Testing tier shows $1,900 a month at $300,000 average monthly media spend, as listed on 12 October 2026.
Best for retail or ecommerce teams wanting testing priced as its own tier.
Geo-test calibration and the causal model sit on its Full-Funnel MMM and Enterprise tiers.
SegmentStream
Their own words: the marketing measurement engine for teams.
Describes expert-led geo holdout tests with synthetic control and an A/A check, plus cross-channel attribution.
Scoped to your business, priced after discovery, in its words.
Best for teams wanting a high-touch partner: a platform plus a marketing science team.
Sold as a high-touch engagement with ongoing consulting, which it calls a solution, not a tool.
Haus
Their own words: the AI-powered incrementality platform leading enterprises use to optimize tens of billions in annual marketing spend.
Describes GeoLift, Time Tests and Fixed Geo Tests configured with its expert team, plus Causal MMM built on your experiments.
Four plans, each leading to a demo, so pricing is quoted on request.
Best for teams wanting experiments first, with a model built on them.
Its pricing page lists Causal MMM on the Plus and Enterprise plans.
The free and open-source options
- GeoLift, from Meta: geo experiments with synthetic control methods.
- CausalImpact, from Google: an intervention's effect on a time series, such as a campaign launch or pause.
- Meridian GeoX, from Google: geo experiments, alone or as priors for a Meridian model.
- Platform lift studies: free and quick, but run by the platform whose budget is evaluated.
Why test design matters more than the tool
- The comparison group: its history must track the test group.
- How long: across 123 of our experiments, 27% of tests under two weeks reached significance, against 71% at four to six weeks.
- The smallest detectable effect: agree it before the test, in writing.
What a test costs in revenue
- Median exposure: 0.7% of revenue, across 15 of our geo experiments with a clear read. Nine in ten exposed under 2.7%.
- Scale-up tests: they add spend, so they put no existing revenue at risk.
How to choose between them
- A standing testing programme: Haus or Measured.
- Retail or ecommerce, with a published price: Sellforte.
- A high-touch partner: SegmentStream.
- Tests that change the plan and the work: Cassandra.
- A nonprofit measuring donations by channel: Cassandra, used by charity: water.
- In-house data science: GeoLift, CausalImpact or Meridian GeoX.
What this page does not do
- No product tests. Vendor statements come from their own pages, read on 12 October 2026.
- No ranking. The order is not a verdict.
- It ages. Out of date? Write to hello@cassandra.app.
Cassandra is an AI marketing brain for growth teams: a Bayesian marketing mix model checked by live geo experiments, doing the work within the rules the team sets. Start for free with your website and data, or book a demo.
How to decide
- How will you choose the comparison regions? The answer should describe a method.
- What is the smallest effect this design could detect? A provider who computed it designed the test.
- What changes when the result lands? A result that updates a model of the whole mix keeps paying back.
Questions
Which incrementality testing tools are best?
It depends on the buyer: Haus for experiments first, Measured for enterprise brands, Sellforte for retail and ecommerce, SegmentStream for a high-touch partner, Cassandra for tests that move budgets and ads.
Are there free incrementality testing tools?
Yes. Meta's GeoLift and Google's CausalImpact and Meridian GeoX are free open-source packages.
How long does an incrementality test need to run?
Across 123 of our own experiments, 71% of tests running four to six weeks reached significance, against 27% for tests under two weeks.
How much revenue does a geo test put at risk?
Across 15 of our own geo experiments with a clear read, the median share of revenue exposed was 0.7%.
Is this list complete?
No. Other vendors also run geo experiments. Recast, for example, describes GeoLift experiments that feed its marketing mix model.
Which incrementality testing tool suits a nonprofit?
Any tool here needs regional structure or an addressable audience to build a comparison group. Cassandra measures fundraising campaigns with geo tests and a marketing mix model, and charity: water used it to bring donor acquisition cost from $123 to $98.