Google has a beta experiment that compares two sets of assets within the same PMax asset group.
How it works:
Control group: your existing assets
Treatment group: the alternatives you want to test, new creatives or existing ones
Traffic split: you decide how traffic is divided between the two
Success metric: you pick one, like conversions, value or clicks
Experiment Guidance estimates how long the test needs to reach statistically significant results. Google recommends running it for at least 4 to 6 weeks.
It is a beta, so not every account may see it yet.
Spotted by Thomas Eccel.
