Performance Max is a single campaign type that places ads across every Google surface — Search, YouTube, Display, Discover, Gmail, Maps — and decides for itself, in real time, where to spend your money. The promise is simplicity. The reality is that, without the right inputs, it spends a lot of that money on places you would not have chosen.
A Pmax campaign is only as good as the signals you give it. The three that matter most:
These are not targets — they are hints. Done well, they nudge the algorithm towards the right kind of buyer in the first few weeks. Done lazily (a couple of in-market segments, no first-party data), they leave Pmax to wander.
Headlines, descriptions, images, video, sitelinks, logos. Pmax assembles ads from this library on the fly. Sparse asset groups produce poor ads; we typically need five to ten times what most accounts start with, and we organise them around themes rather than dumping everything into one pile.
For retailers, the Merchant Center feed is the campaign. Missing GTINs, weak titles, broken images, mismatched prices — every one of these limits how well Pmax can perform. We spend more time on feeds than on the campaign settings themselves.
When Pmax launched, it was almost a black box. Since then, Google has restored several useful controls — campaign-level negatives, brand exclusions, channel reporting, search-term insights. We use them. The campaign that ran well two years ago can be tuned considerably more now.
Pmax reporting is still less transparent than older campaign types. We work with what is available, document what we cannot see, and never pretend the box is fully open.