For years the PMax black box was almost total. Google has gradually been opening cracks —the latest one a channel performance report— without ever giving you what you would take for granted in any other campaign: spend and conversions by network at the same level of detail. This lesson goes through what exists today, how to read it and what is still missing.
The «Channel performance» report
Inside the PMax campaign, the channel report shows performance metrics by channel (Search, Shopping, Display, YouTube, Discover, Gmail, Maps): impressions, clicks, cost, conversions, value. It is the answer to "where is the money going" that used to be missing. What you need to know:
- It is subject to thresholds: channels with low volume appear aggregated or without detail.
- Conversions by channel follow the campaign's attribution (and view-through conversions from video/Display can inflate those channels).
- It comes with "optimisation suggestions" by channel: read them for what they are, recommendations.
- It is a per-campaign report; for the account you have to add them up.
How to read it: the split of cost by channel against the split of click-through conversions. A channel with 30% of the cost and 5% of the click-through conversions is the usual suspect (Display or video), and the lever is exclusions (lesson 4).
PMax search terms
PMax shows its search terms (those with enough volume; the rest grouped into categories) with impressions, clicks, cost and conversions. Three uses: seeing how much is brand (and how much it was stealing from you before you applied brand exclusions), discovering demand your Search campaigns don't cover, and feeding negatives (account-level negatives and PMax campaign negatives, which Google allows within limits).
Placements
A report of where the PMax ads showed (domains, apps, YouTube channels) with impressions —and, in a limited way, a little more— for part of the inventory. It is the crack that lets you see fraud (module 5): domains and apps you recognise as junk go to the account-level placement exclusion list, the only one PMax respects.
Asset groups and assets
Performance by group (cost, conversions, value) and, inside it, the label for each asset. It lets you compare messages/audiences with each other and work on the pieces. With no breakdown by channel inside the group.
Reconstructing where the money goes: the method
- Channel performance: split of cost and click-through conversions.
- Search terms: the share of the Search channel that is brand vs generic; conversions from each part.
- Placements: the quality of the Display/video channel (junk vs legitimate).
- Fingerprints (lesson 1): characteristic CTR/CPC by channel as a cross-check when the thresholds trim the data.
- Total account uplift when switching it on or off (lesson 6).
With this you can build a table per PMax campaign: channel · % cost · % click-through conversions · quality (brand/generic, clean/junk) · action. It is the report Google ought to give you and doesn't, quite.
What still can't be seen
- Spend by term in the long tail (privacy thresholds).
- Placements with their full cost.
- Click-through vs view-through conversions by channel, clearly separated.
- The split by channel inside each asset group.
- Direct control over the split: it still doesn't exist; only incentives and exclusions.
Judging each channel by its own yardstick
A single ROAS for the campaign mixes brand (which would have converted anyway), Shopping (which competes with your standard Shopping), Display (with view-through) and YouTube (with views). Rules by channel:
| Channel | How to judge it |
|---|---|
| Search (generic) | Like a Search campaign: CPA on click-through against target |
| Search (brand) | It shouldn't be there (brand exclusions); if it is, discount it |
| Shopping | Like Shopping: ROAS by margin; compare it with the standard campaign |
| Display / Discover / Gmail | On clicks, view-through separately; clean placements |
| YouTube | On clicks; views as awareness; don't mix them |
💡 Ninja trick: the channel report is a step forward, but it arrives per campaign and with thresholds. The GAQL analysis in the scripts is still the way to have the complete table every night, per campaign and per account, with history — and the way for Ninja Shield to turn the placement list into account exclusions before the Display channel takes another month's budget.
What you should remember
- Today you have channel performance, search terms, placements and assets; all of them with thresholds.
- Reconstruct with channel + terms (brand/generic) + placements + fingerprints + uplift.
- Still invisible: the long tail, the full cost per placement and the split inside each group.
- Each channel by its own yardstick: Search on clicks, Shopping by margin, Display/YouTube on clicks with view-through kept separate.