How To Optimise Your Google PMax Campaigns

In this post I am going to show you how to optimise your Google Performance Max (PMax) campaigns.

According to a recent poll (by Mike), over 70% of Google ad spend uses this format. That is some like 70% of $60 Billion dollars in round numbers. ;)

But the kicker is that Google doesn’t really show us behind the curtain, making it harder for us to optimise intelligently.

So let’s give you a process to fix this and stress test this against yesterday’s announcements from Google Ads.

PMax Optimisation Process

A really good PMax campaign is a progression of improvements. But you have to know the serenity prayer before you start.

That is:

“God grant me the serenity to accept the things I cannot change, courage to change the things I can, and the wisdom to know the difference.”

More on this later..

1.0 Beginner Tasks (Fundamentals)

1. Products available in the Merchant Center Feed
2. Title’s, descriptions SEM optimised.
3. Pricing in market.

2.0 Intermediate Tasks

1. Custom Labels Added to products.
2. Ad Copy, Images & Videos optimised.
3. Pmax structure that makes sense

3.0 Advanced Tasks.

1. Bidding Strategies Appropriate (No link expansion)
2. Audience Signals
3. Split Testing

1.1 Products available in the Merchant Center Feed

You may not want to advertise every product. Think low margin or low revenue items. Some items you are super keen to sell. Think high inventory or high margin.

To make sure you have the mix right open up your Google Merchant Center and look to see that all the products you want to advertise are available.

There may be issues with products listed that affects their ability to show in ads. Have a look at the diagnostics tab and deal with the issues at the bottom of the page.

Action Item: Review your feed for missing products and for errors against current products.

1.2 Title’s and Descriptions SEM Optimised.

I really like Mike Rhodes approach to bulls eye targeting. In the middle of the bullseye is your brand, then next ring out is the brand categories, then competitors, competitor categories and then generic on the outside.

The point is many more people search for the generic terms but they are closer to a transaction the closer you get in.

This means our titles and descriptions need to cater to both. Google search your brand terms and the generic terms to see how the product titles are optimised.

You might see structure like:

[brand name] [Product Name] [Generic Term] Size [X] Colour [Y] [Retailer Name]

eg [Nike] [Free Run 2] [Mens Shoes] [White] [Size 10.5] [Foot Locker]

[ ] Action Item: Google Search your products and note the structure for your industry. Read the descriptions and include the relevant keywords into your titles and descriptions.

1.3 Pricing In The Market

I used to sell a lot on ebay. At one stage I had the biggest supplement store on the platform and could not keep up with demand.

Part of the reason was we were where too cheap. Like all things there is a normal distribution of pricing that is the bell curve in effect.

You need to be in the middle not at the extremes. Too much and you get busy without profit. Too little you get no business and no profit.

Take a look at your Google merchant center and get familiar with the price competitiveness report. Google is comparing all the merchants selling a particular GTIN and suggesting a click weighted price.

If you are lucky not to be selling the same as lots of other retailers take a look at the Price Insights tab and predicted conversion increases. Workout your own predicted gross margin increases per month to see if this is worth testing.

[ ] Action Item : Review prices in Google Merchant Center

2.1 Add Custom Labels To Your Products In The Feed

Remember point 1.1 where you may not want to advertise all your products? Custom labels in a Google feed are helpful to turn product off and on in advertising campaigns.

Some example uses I like are:

• Custom label 0 - Margin (High, Medium or Low) May not want to advertise products with low margin.
• Custom label 1 - On Sale (Sale or Full Price) May want to advertise full price items only.
• Custom label 2 - Product Category (Refer back to your site structure) May not want to advertise out season items like womens high boots in summer. (I have seen labels used for the 4 seasons too)
• Custom label 3 - Promo code. You might want to apply an ad promotion to a set of products like a summer clearance spanning multiple categories. Eg 20% off the summer range of shoes including sandals and espadrille flats.
• Custom label 4 - Top seller or not. (Top 20) - think about the top 20% of products that make 80% of the sales. This is a great campaign to autoscale.

You will need to create place holders in your CMS for these labels and sync them into the merchant center feed.

[ ] Action item: What ways would you like to slice and dice your products for advertising. Decide this then add labels into your products.

2.2 Ad Copy, Images & Videos optimised.

For a lot of businesses this is hard. ChatGPT and other AI tools like Jarvis will make the copywriting easier but people still need to know the basics.

You put rubbish in you get rubbish out.

Lets start with images for a moment. Think beyond the front back, top, bottom, left and right. There are details to shoot for people to pinch and zoom on like zippers, toes or heels.

But there are other types of images like styling suggestions, in use images, or ready to consume type images.

Then there are informational type images like iconographry call outs or nutritional panels etc.

Video is a mixture of these elements above.

Copy is something I love deeply and try to make what you write “punch someone in the face”.

Most ad copy is boring as. Google your products and take a look. For PMAX ads we can write 5 headlines, 5 long headlines and 5 descriptions.

Think about writing something to address:

1. How a person should feel after buying your good
2. What does someone get from buying your product
3. Who will notice the difference after people get the benefit of your product
4. What have other customers said about this product
5. What are the punch in the face benefits.

[ ] Action Item: Rewrite your PMAX ad copy to be punch in the face bold.

2.3 PMAX Structure That Makes Sense.

This is already getting long so I will be brief here. The old rule of Google ads was to follow the same navigation as your ecommerce sites menu. Set up 1 campaign per major category.

This makes sense in most cases as you will want to increase or decrease your budget based on product categories performing or not.

PMax campaigns need a lot of conversions to auto optimise by machine learning. It used to be 50 conversions in 10 days, but I assume it is less and faster now.

So considering the structure in 2.1 above you might want to just advertise the proven winners. You will need a subset of all the products in a category.

In the PMax campaign go to your Pmax campaign. Click on Asset Groups, then click on Listing Group. You can then divide up by custom labels.

[ ] Action Item: Review your campaign structure and decide if you want to advertise all products in a category or a subset of proven winners.

3.1 Bidding Strategies Appropriate

There are 2 major types of bidding strategies for PMax. Maximise conversions or maximise conversion value.

The difference is for Maximise Conversion Value, PMax might try to sell higher priced items and ignore lower priced items. Maximise conversions is just trying to get as many conversions as possible without regards to maximising revenue.

Both approaches have their application.

What is more advanced is to set targets for the each strategy. Eg a 400% target ROAS. Then each fortnight review the actual results and sneak up the target by 10-15%.

This feels like stretching the machine learning or getting in the draught of a big truck if you ever ride a motorbike.

[ ] Action Item: Review your bidding targets and know how close are they to the actual results. Make the targets within 10-15% of the actual and review performance in 2 weeks.

3.2 Audience Signals.

This may not be as effective going forward as Google becomes more automated. But the strategy is to make an audience of people who have viewed, added to cart and bought a certain category.

You can create this audience in your Google Analytics account and in GA4 this will automatically sync across to Google ads.

You can also do this inside your email marketing system and create a custom audience that way.

The benefit of this is that the PMax campaign has a great signal to know who to look for as a potential buyer for this product. It is not keyword driven apart from you know the name of the category that the audience was built from.

Google has a thousand other signals about these people that we don’t know and it is their AI that is profiling people and importantly similar audiences to show your Pmax videos and images to. It is making a little discovery campaign out in front of a search ad campaign.

[ ] Action Item: Create segments in Google Analytics 4 based on visiting, purchasing or not purchasing a category of products.

3.3 Split Testing

Back to the serenity prayer. Historically Google has not allowed us to know enough about what is working or not. The “Wisdom to know the difference” part.

They have billions of $ of ad spend and could only tell us if our assets were High Performance, Good or Poor.

To overcome this Mike Rhodes published a script that gives a breakdown of where our advertising dollars are being spent eg videos, images or search so we can then duplicate our asset groups and change out a poor performing asset with a better one.

You can get and install Mike’s reporting script here on Github and install it to your Google Ads account. Tools & Settings > Scripts > + new Script (Paste in the code and add your own spreadsheet url as per instructions in the code.)

With this script and reporting spreadsheet in place you can see the CTR, Cost of Acquisition and ROAS of different Asset Groups in the PMax campaigns. This is a million times better than High Performance, Good or Poor.

[ ] Action Item: Install the reporting code to your Google Ads account scripts. Duplicate your asset groups in the PMax campaigns and see which performs better over time. When statistically significant pause the underperformers, duplicate the winner and try to beat it with better images, copy, videos and signals.

So there you go. There is a lot of work to be done here and if you do get this all right you will be way in front of a 90% of other advertisers.

Let me know if you feel I have missed anything. (I have knowingly excluded location bid modifying and ad schedule / day parting)

Sorry for such a long post.

Ant

PS Yesterday 24/02/2023 Google Ads released a raft of changes to PMax campaigns. Their ads Liason twitter account unpacks it here. From what I read these fundamentals have not changed. Reporting and experimenting are going to be easier.

https://twitter.com/adsliaison/status/1628787533516603395?ref_src=twsrc%5Etfw">February