Everything so far has been written with Display in mind. But fraud has moved to where there is less control: PMax, video and Demand Gen buy the same rubbish inventory with partial reports and no per-campaign exclusions. This lesson locates the entry points in each type and the common defence.
PMax: the favourite ground
PMax buys Display and video without you choosing placements, and its placement report is partial (module 1). For a farm, a PMax campaign with a large budget is ideal: it gets into their inventory, they get paid, and the advertiser only sees an aggregate ROAS. Signals that rubbish is getting in:
- The Display/video channel with high cost and no click-through conversions at all in the performance-by-channel report.
- Placements in the PMax report showing absurd domains and filler apps.
- The campaign's CPA getting worse while the Search channel stays the same.
- View-through conversions growing: the rubbish "sees" a great deal.
The defence: the account-level placement exclusion list (the only one PMax respects), account-level app and content exclusions, and, if it persists, squeezing PMax back to the channels that contribute (you cannot pick channels, but you can tighten the target ROAS so the cheap channels with no conversions stop getting in).
Video and Demand Gen: video partners and bought views
- Google video partners: video inventory outside YouTube (sites and apps with players). This is where the cheap views live, and the autoplay players with nobody in front of them. The signal: a sky-high view rate with zero interaction. The defence: untick video partners when you create the campaign (video and Demand Gen both allow it) unless you have measured them.
- Rubbish YouTube channels: channels of generated videos with millions of views and a non-existent audience. They show up in the video placement report; you exclude them as a placement (channel) — at account level, so it also affects Demand Gen and PMax.
- Children's and "made for kids" content: content exclusions (limited inventory) and category exclusions.
Shopping: comparison shopping clicks and price bots
In Shopping the fraud is different: there are no farms, but there are price comparison bots and scrapers that load product pages and sometimes click, and competitor clicks on expensive products. Signals: clicks with no real session in Analytics, spikes of clicks on specific products at fixed hours, data centre IPs. The defence: IP exclusions with an expiry, Visitor Shield on your site (lesson 3), and keeping an eye on products with disproportionate clicks and no add-to-cart (Shopping Ninja flags them as "spends without selling").
The common defence: what they all respect
| Defence | Display | Video | Demand Gen | PMax | Shopping |
|---|---|---|---|---|---|
| Account-level placement exclusion list | Yes | Yes | Yes | Yes | — |
| Account-level app exclusions | Yes | Yes | Yes | Yes | — |
| Account-level content exclusions | Yes | Yes | Yes | Yes | — |
| Account-level IP exclusions | Yes | Yes | Yes | Yes | Yes |
| Untick partners (search/video) | — | Yes | Yes | No (no control) | Yes (search partners) |
| Per-campaign exclusions | Yes | Yes | Yes | No | Partial |
The conclusion is the rule from module 1: set everything universal at account level. An account list maintained every night protects five campaign types at once; a per-campaign exclusion protects one.
The routine
- Daily (automated): new placements from Display, video, Demand Gen and PMax → score → account exclusion; network clustering.
- Weekly: the PMax channel report and video partners; apps; false positives.
- Monthly: click-through CPA by channel/campaign before and after; IPs that expire; the Safe Sites list.
💡 Ninja trick: Ninja Shield reads the placements of every automated campaign (Display, video, Demand Gen and PMax) and writes to the account exclusion list, which is why a single script protects the whole account. And because PMax does not let you see the cost per placement, the Shield decides on the domain's score (not on its spend in your account): a farm is a farm even when Google will not tell you how much you have paid it.
What you should remember
- PMax is the favourite ground: inventory with no per-campaign control and partial reports; the signals are in the channel and placement reports.
- Video/Demand Gen: untick video partners; exclude rubbish channels at account level.
- Shopping: bots and competitors → IPs with an expiry and Visitor Shield.
- The defence they all respect: account-level exclusions (placements, apps, content, IPs), maintained every night.