Most teams manage PMax. The accounts that compound engineer the signal environment around it. This hub is the complete operating reference — the architecture essay, the 10-point signal audit, two working Lab experiments, and a downloadable checklist you can take into a Monday morning planning meeting.
Smart Bidding inside Performance Max is a machine-learning system. Like every machine-learning system, the quality of its output is bounded by the quality of its input. The input isn't your bid strategy or your daily budget — those are constraints, not signals. The input is the corpus of signals telling the model what a valuable conversion looks like, who valuable customers tend to be, what creative variants resonate with which audience clusters, and which conversion events are worth pursuing at the margin.
When teams complain that "PMax is a black box," what they usually mean is that they can't see placement-level reporting. That's a real transparency limitation. It is not, however, an optimization problem. The optimization is happening. It just may be optimizing against signals that look nothing like the goal the team thinks they set. The whole argument — including the cleanest failure mode (firing valueless "lead" conversions and watching Google find the cheapest path to garbage form fills) — is laid out in the anchor essay.
Read the full essay: Performance Max Isn't a Campaign Type. It's a Signal Feedback Loop. →
Every PMax account compounding in 2026 is engineering five signal layers underneath the campaign. Every account stuck is missing at least three.
Run this before you touch a bid strategy. The order matters — earlier items gate later ones. Score each yes / partial / no. Anything below 8/10 is a signal-architecture problem masquerading as a PMax problem; fix the signal layer first and campaign performance follows.
Designed to be run in a single 90-minute working session with the channel lead, an analytics partner, and someone who owns the CRM.
Two of the live experiments in the Uncommon Move Lab are testing the architecture above against real PMax accounts. Hypothesis, method, result, and what changed in the thinking, published as the work happens.
A printable one-page version of the 10-point audit above, designed to be marked up in a meeting and walked out the door. Use it before the next quarterly review, the next vendor pitch, or the next "why isn't PMax working?" conversation.
One page, ten boxes, no marketing fluff. Anything scoring below 8/10 is a signal-architecture problem, not a campaign problem.