TPE #118: 5 things you must know about pMax (that most people still don’t)

Read time: 4 minutes

GM, Miles here with the first PPC Edge issue of 2025!

I hope you had a fantastic holiday period — I sure did.

I’m back with fresh new content to help you make the most out of Google Ads this year.

Today, I’ll be sharing 5 things you must know about Performance Max — that still a lot people don’t.

Understanding these things will help you prevent getting bad results. And we all want that, right?

Let’s dive in!

5 things you must know about Performance Max (that might sound obvious, but most people are still unaware of).

Performance Max campaigns have been around for more than 3 years now, and we’ve tried our best to demystify and make sense of the black box that it is.

Last week, I recorded the new Performance Max & Shopping module for our upcoming Google Ads Success Path program (exclusively available in The PPC Hub).

It’s full of gems, fundamental insights, and advanced tactics.

And with some of those fundamental insights, I feel like ‘everyone already knows this’.

But when I look online and audit accounts, I see that a lot of the fundamental mistakes are still being made.

So here are 5 things you must know about Performance Max (that might sound obvious, but most people are still unaware of):

1. You can add negative keyword (lists) via support.
2. Audience signals are NOT direct targeting.
3. Search themes can lead to cannibalization of Search.
4. Performance Max over-inflates itself with brand conversions.
5. You can see spend allocation across channels with a script.

Let’s dive in on each of these!

1: You can add negative keyword (lists) via support.

Since the beginning, we haven’t been able to add negative keywords to Performance Max campaigns directly.

However, there’s a workaround: you can fill out the ‘Performance Max Campaign Modification Request Form’ to get Google support to add negative keywords or negative keywords lists to your pMax campaigns!

That’s a great way to exclude brand traffic or underperforming search terms.

It’s a simple form that you can fill out to ask Google to exclude any keyword, topic, or placement.

It speaks for itself:

1. Fill out all relevant details about your account.
2. Select what you want to exclude and at what level.
3. Download and fill out the ‘pMAX: Request Template’.
4. Upload the template, give consent and submit the form.

And voila, Google support will now add your negative keywords (lists) to your pMax campaigns!

p.s. Self-serve campaign-level negative keywords for Performance Max are available in Beta right now. I hope they will soon be rolled out to all accounts!

2: Audience signals are NOT direct targeting.

With pMax campaigns, you can set up Audience Signals to inform Google what audience segments are valuable to your business.

However, what many people don’t understand: audience signals are NOT direct targeting.

They are mere signals, used to guide Google's algorithm in the right direction.

But eventually, Google can and WILL go beyond your signals.

The official documentation confirms it: “Performance Max may show ads to relevant audiences outside of your signals if they have a strong likelihood of converting to help you meet your performance goals.”

It surprises me how often I still hear people talk about complex audience signal layering strategies for pMax, as if it has any impact on your campaigns.

It does not and it's a waste of time.

Audience signals are mere suggestions that give us a fake sense of control.

They are NOT used for targeting, and Google WILL eventually go beyond them.

3: Search themes can lead to cannibalization of Search.

When you run Search and Performance Max campaigns together, this happens a lot:

• Search stops spending.
• Performance Max takes over most traffic.

This can be frustrating, especially when you want to control your traffic with well-structured Search campaigns.

I see many people struggle with this because they don’t deeply understand the ins and outs of Performance Max, its mechanics, and how internal matching works between campaign types.

When you use Search Themes in pMax, a seemingly harmless feature, you basically tell Google that you don’t mind whether a specific search term gets picked up by your Search or Performance Max campaigns. (Because they get the same prioritization in the auction as your identical Phrase and Broad Match keywords)

This graph effectively shows how the Internal Matching Hierarchy works between Search & Performance Max campaigns.

For a more detailed case study (with a real-life example) on how Search Themes in pMax can negatively impact your Search campaigns, check out issue #108 of The PPC Edge here.

4: Performance Max over-inflates itself with brand conversions.

You can’t trust your Performance Max results.

Why? Because they’re heavily inflated by Branded Search conversions. This makes pMax look better than it actually is.

Performance Max heavily cannibalizes your other campaigns and LOVES to take credit for every single conversion. People who search for your brand would’ve converted anyway, so why should you let pMax take credit for it?

Since Google launched Performance Max in 2021, I’ve been super vocal about why I think you should exclude branded traffic, but unfortunately I still see many accounts in which brand is still included in pMax campaigns.

Here’s the simple solution:

1. Analyze your share of brand in pMax (with a script).
2. Exclude brand from pMax with Brand Exclusions or via support.
3. Catch brand traffic in Branded Search and Branded Shopping campaigns.
   
   

For more context on why this is important and how to fix it, check out issue #92 of The PPC Edge.

5: You can see spend allocation across channels with a script.

Performance Max is a giant black box and Google is not telling us how much we spent on each individual ad network (Search, Shopping, Video, Display, etc.).

Luckily for us, Mike Rhodes built a fantastic script that allows you to see the spend allocation and performance per network.

It’s an absolute MUST in every account that runs Performance Max campaigns.

Here’s a guide that explains it into more detail, with links to get the script.

Use these 5 things to create better Performance Max campaigns that actually perform well.

To recap, here are the 5 things you must know about Performance Max (that might sound obvious, but most people are still unaware of):

1. You can add negative keyword (lists) via support.
2. Audience signals are NOT direct targeting.
3. Search themes can lead to cannibalization of Search.
4. Performance Max over-inflates itself with brand conversions.
5. You can see spend allocation across channels with a script.

And that’s all for now.

I hope you learned something new today. And if not, you just realized your knowledge of pMax is already really good!

Have a great day ahead, and see you next week :).

Cheers,

Miles (& Bob)