How Switching from MMP to Firebase Events Changed the Performance of my Google App Campaigns

I ran an experiment switching the optimisation event in my Google App Campaigns from an MMP event to the equivalent Firebase event, keeping bids, budgets, and creatives constant.

The result? Significant increases in installs and post-install events across most markets, but with a noticeable dip in Day 1 ROI. This test highlights the classic growth tension between scale and efficiency, and how optimisation signals can materially influence performance.

For a full breakdown of the experiment and detailed market-level results, read the complete article on Medium here.