
Toward the End of Silos: Data-Driven Budget Arbitration
For years, testing on Google Ads has been limited to variables internal to a single campaign type, such as A/B tests of ads or bidding strategies within Search. The arrival of "Mix Experiments" radically changes the game by allowing comparison of two fundamentally different account structures. Based on our account observations, the question is no longer whether one keyword performs better than another, but whether allocating a portion of the budget to Performance Max generates additional conversion volume compared to a classic Search structure.
This technical innovation responds to a growing need for transparency among Traffic Managers. By comparing, for example, a "Pure Search" strategy to a "Search + PMax" mix, Google establishes a rigorous protocol to isolate the real incremental contribution of each channel and avoid performance duplication. The challenge for brands is to scientifically validate that AI doesn't simply shift existing conversions, but actually expands the audience pool through inventory like YouTube or Discover.
A Rigorous Testing Protocol to Secure ROI
The strength of "Mix Experiments" lies in its statistical approach based on traffic or cookie splitting. Specifically, Google Ads randomly divides the audience to ensure both test arms evolve under identical market conditions. This rigor eliminates seasonal biases or competitive bidding fluctuations that typically pollute before-and-after analyses.
The direct impact on CPA is immediate: by identifying the most efficient configuration, brands avoid budget waste on underperforming formats. For advertisers managing substantial budgets, this lever enables surgical precision in managing incrementality. However, the learning phase remains a key factor; as with any machine learning-based solution, we recommend test cycles of 4 to 6 weeks to stabilize data signals and obtain statistically significant results.
AI as Copilot: Optimizing Creative and Semantic Resources
The integration of these tests aligns with Google's overall vision of "augmented marketing" promoted through Gemini. Beyond simple performance comparison, these experiments highlight the effectiveness of creative assets across different touchpoints. If a mix including Performance Max outperforms an isolated Search campaign, this confirms the need to invest heavily in high-quality visual resources to feed the algorithm.
Furthermore, this feature allows for refined audience strategies. By analyzing how campaigns respond to new intent signals detected by AI, brands can adjust their messaging in real-time. The challenge is to maintain strict brand consistency while giving artificial intelligence the necessary flexibility to optimize delivery. SEA management becomes hybrid: bid mastery gives way to a nuanced understanding of how tools filter information.
Our Google Ads agency supports brands in structuring and activating audience strategies adapted to their actual volumes and performance objectives.


