Google Ads Gets Portfolio-Level Experiments. Control Groups Still Exist. You Are Welcome.
Google Ads now lets advertisers test budgets, ROI targets, brand controls, location settings, and campaign changes across a portfolio rather than one campaign at a time. The AI Max for Search experiments also preserve more existing settings, so you can actually compare your current strategy against the AI-driven one without everything collapsing into noise.
This illustrates a principle I try to teach every semester: isolated testing produces isolated conclusions. The mechanism here is portfolio-level experimental design with a held-out control group. When you test a strategy across multiple campaigns simultaneously while keeping a control arm, you learn whether the change works at scale, not just whether it worked once in a single campaign that happened to have favorable conditions.
Google Ads is rolling this out for advertisers managing portfolio-level budgets and bidding targets. Brooke, Director of Growth Marketing at Smith Micro Software with over 10 years of paid media experience, is cited as a practitioner voice.
- Sign into your Google Ads account and navigate to a campaign you actively manage. Look for the Experiments option in the left sidebar. If you see it, you have access to the testing framework.
- Create a new experiment by duplicating your campaign as the control and a modified version as the test arm. Change one variable only, such as a budget or ROI target. Expected outcome: Google will split traffic between both versions and report performance side by side.
- Let the experiment run for at least two weeks, then compare ROI metrics between the control and test arm. Expected outcome: you will have a defensible answer about whether the change helped or hurt, rather than a hunch.