Google Marketing Areas (GMA)

What Are Google Marketing Areas?

Google Marketing Areas solve a central problem in performance marketing: how do you measure the true advertising effect of your campaigns? Through controlled geo-experiments in comparable regions, you can finally prove whether your Google Ads campaigns actually generate additional conversions or whether users would have purchased anyway without ads. This makes GMAs an essential tool for data-driven budget decisions.

Google Marketing Areas (GMA) are geographic regions that Google has specifically defined for advertising experiments and geo-tests. Similar to DMAs (Designated Market Areas) in the US, GMAs divide a country into distinct areas suited for controlled experiments. The advantage over conventional geographic units: GMAs are designed so that they have similar user structures and minimal overlap.

In practice, you use GMAs for geo-experiments, in which you run a campaign in certain regions and use other regions as a control group. By comparing business results in test and control regions, the incremental effect of your campaign can be measured. This method is especially useful for campaign types where user-level holdback experiments are not possible, such as YouTube or TV campaigns.

To run a geo-experiment, you should select at least four to six GMAs as a test group and an equal number as a control group. The test period should be four to eight weeks. Use Google’s Causal Impact method for evaluation. GMAs are currently not available for all countries. Check in Google Ads Help whether GMAs exist for your market.