Google has launched Meridian GeoX, an open-source incrementality testing tool, alongside Meridian Studio for enterprise MMM. The tools aim to democratise measurement that was previously only available to the largest advertisers.
Google is not just giving away a measurement tool. It is trying to become the default infrastructure for how advertisers prove value across channels.
Google has launched two measurement tools that could reshape how advertisers prove their spend is working. Meridian GeoX is a free, open-source tool for running geo-based incrementality experiments. Meridian Studio is an enterprise platform for managing marketing mix models at scale on Google Cloud.
GeoX works by comparing ad performance across geographic regions to isolate incremental lift. It has been in testing in select markets since 2022. The open-source release means any advertiser with basic analytics capability can now run the same kind of incrementality experiments that previously required dedicated measurement teams and expensive third-party vendors.
Google has been testing GeoX in select markets. The open-source release now makes geo-based incrementality testing available to any advertiser.
Meridian Studio sits on top of this as the enterprise layer. It provides cloud-powered infrastructure for running complex marketing mix models with multiple data sources, automated modelling and scenario planning. Think of it as the managed version for teams that want incrementality at scale without building their own data science stack.
Why it matters
Incrementality testing has been the gold standard for measurement but practically inaccessible to most advertisers. The cost, complexity and data requirements meant it was reserved for brands spending millions per month. GeoX lowers that barrier significantly.
The strategic angle is also important. Google has a vested interest in advertisers proving that Google spend drives incremental outcomes. Open-sourcing the tool positions Google as the neutral measurement layer, even though it is also the platform being measured. That tension will not go away, but the tooling itself fills a real gap.
For Australian advertisers, geo experiments are particularly useful given the natural geographic segmentation of state-based markets. Running a test across NSW and Victoria with holdout regions is straightforward and the population sizes are large enough for statistical significance.
What to do about it
Google just made the most credible form of ad measurement free. The advertisers who use it will make better decisions. The ones who ignore it will keep guessing.