Looking under the hood of Google Performance Max (PMax)
Ever since Google launched Performance Max, or PMax for short, it has been both a blessing and a curse for digital marketers. It promises to do the heavy lifting for you and is simple to set up, which on the face of it sounds too good to be true.
Work on enough accounts and you see the good and the bad. On one account PMax is a shining unicorn; on another it’s a tired donkey. One of the most common frustrations is that it can feel like a black box, with little visibility of what’s going on.
Here are a few practical tips to look into the detail of PMax and regain some control over your campaigns.
Since this post was first written, Google has added several of the controls advertisers asked for. Campaign-level negative keywords rolled out to all advertisers in early 2025, with a limit of 10,000 per campaign, and PMax now has a search terms report and a channel performance report under Insights and reports. I’ve updated the sections below to reflect this.
1. The insights report
In the Insights tab, the default view covers the last 7 or 28 days. Switch to a custom date range and you can look back much further, giving you a good span of data to analyse.
Once you’re looking at a long enough window, you can pinpoint which search themes are driving activity and decide whether you need dedicated Search campaigns, or whether there’s data to tidy up.

2. Asset group table view
When you drill into your asset groups, the default summary layout shows how your assets look and a few key notes. What it’s missing is the performance metrics.
Switch to table view and you can compare each asset group in the campaign side by side. You can see which groups are working, which audience signals they use and how they compare. It’s a simple tip that helps you decide which asset groups to keep and which to remove.

3. Channel reporting and the Agencysavvy script
When you run PMax, you can’t tell Google how much weight to give Search, Shopping or video. You’re at the mercy of the algorithm. What you can do is monitor which channels are driving the campaign and its conversions.
Google now includes a channel performance report in PMax, under Insights and reports. Before that existed, the Agencysavvy PMax script was the best way to see the split between Search, Shopping and video, along with asset group and product performance, and it’s still useful for tracking trends over time.
In the example below, the split between Shopping and Search is fairly even on some campaigns, while others lean heavily towards Search.

If Search is doing the work
More defined Search campaigns may give you better control and results.
If Shopping is driving
An asset group with only a listing group may be the better setup for your campaign.
I’ll review your Performance Max campaigns and send you the three changes that would make the biggest difference, free.
Putting it into action
Once you know the split on your Google Ads campaign, you can see where most of your attention needs to go.
Focus your attention
Use the channel split to see whether Search or Shopping deserves most of your time.
Test asset groups
Compare asset groups in table view, then A/B test messaging or audience signals to improve cost per conversion.
Act on search themes
Use longer-term insight data to spot themes worth their own Search campaigns, and exclude those that aren’t relevant.
Negative keywords in PMax: what’s changed
One of the most requested features since PMax launched was the ability to control which searches it shows for. When this post was first written, the only options were account-level negative keywords or asking Google support to add exclusions for you.
That has now changed. Google’s own guidance confirms campaign-level negative keywords are available for all Performance Max campaigns, and Search Engine Journal covered the new channel, search term and asset reporting. Here’s how I’d use them.
Review the search terms report to find irrelevant queries
Add campaign-level negative keywords directly in Google Ads
Use account-level negatives for terms you never want to appear for
Use brand exclusions where brand safety matters
Stuck with your PPC campaigns?
If you need more insight into Performance Max or your campaigns aren’t performing, I’ll take a look and tell you honestly what I’d change first.


