PMax and Search can work together effectively — if managed correctly. If not, PMax can cannibalize impressions from your Search campaigns, hurting overall account performance.

Our recent research showed that:

• 67% of PMax campaigns have search terms that overlap with Search campaigns.
• When search term overlap exists, PMax has more impressions 61% of the time.

Despite this, when search terms are shown from both PMax and Search:

• Search campaigns have higher CTRs 65% of the time.
• Search has higher conversion rates 84% of the time.

Search ad groups are structured so that your ads and keywords are highly related to each other and use a relevant landing page. This structure lends itself to high CTRs and conversion rates.

Conversely, PMax campaigns show ads for a wide variety of search terms. Therefore, PMax ads and landing pages are usually not as relevant to the search terms as in Search campaigns.

Note: These insights exclude PMax campaigns with retail feeds, as they behave very differently to PMax campaigns without feeds.

If your Search campaigns are losing impressions to PMax, it may be due to how your account is set up and managed. In this article, we’ll explore common reasons why PMax shows ads over Search and how to address them.

PMax priority

First, let’s revisit how Google determines which campaign gets priority in the ad auction.

In our PMax cannibalization article, we explained how Google decides whether to show ads from PMax or Search campaigns. Here’s a quick reminder, as it plays a crucial role in managing search term overlap:

Now, let’s look at the seven most common reasons why PMax takes Search impressions:

1. Poor ad group organization leads to a low ad rank

Granular ad group organization is the cornerstone of any effective Search campaign. When ad groups do not have closely matching ads and keywords, the quality score suffers, which leads to a low ad rank.

Many accounts fall into the trap of adding a large number of keywords to an ad group. Since these keywords cover a variety of ideas, to compensate, these advertisers create RSA headlines that include many keywords and aren’t focused on a central theme. However, since Google doesn’t always build the RSAs to match your keywords, this strategy leads to poor ad ranks.

Increasing your keyword’s ad rank can lead to Search campaigns getting more impressions for your top search terms. It can also have a positive effect on your overall outcomes: one company quadrupled their conversions just by fixing their ad group organization.

2. Not adding search terms as keywords

To ensure your Search campaigns are prioritized over PMax, it’s important to understand how Google matches keywords to search terms:

1. Exact match keyword identical to the search term: Search gets top priority.
2. Phrase or broad match keyword identical to the search term: Search should show over PMax, as long as no identical PMax search theme exists.
3. No identical version of the search term as a keyword: either campaign type can be used for a keyword.

When we say identical, we do mean identical. For instance, if you have the keyword Italy tour guide, none of these search terms are considered identical:

• Italian tour guide (word variation)
• Italy tour guides (plural)
• Italy guided tours (word variation)
• Tour guide Italy (different word order)
• Italytour guide (missing spaces between words)

When you see a search term consistently receiving conversions from a Search or PMax campaign, add that keyword to your account.

3. Removing redundant keywords

Google sometimes suggests removing redundant keywords.

If you follow this suggestion, the keyword will no longer be in your Search campaign. If the keyword isn’t in your Search campaign, then either campaign type can show an ad for that search term.

This is why we recommend always ignoring this recommendation.

4. Google auto-apply settings

When auto-apply settings are enabled, Google can automatically make changes to your account. Two of these settings directly affect whether Search or PMax receives impressions.

1. Removing redundant keywords can cause ad-serving issues.
2. Removing non-serving keywords — if a keyword doesn’t receive impressions in a while, then Google marks it as non-serving and recommends removal.

This can create challenges for seasonal keywords:

• Seasonal keywords may receive few or no impressions during the off-season.
• Google removes the keywords as non-serving.
• The following season, the keywords aren’t in your Search campaigns, so PMax takes all the impressions.

You can confidently turn off the auto-apply settings and manually monitor Google’s recommendations.

5. Lost impression share budget & bid strategies

If your Search campaign loses impressions due to a low budget, it becomes ineligible to show ads. This allows PMax to capture those impressions.

If you use different bid strategies for PMax and Search, the bids Google submits into the auction will differ, changing your ad rank.

When you don’t have a keyword identical to the search term, ad rank is one of the priority factors Google uses to determine which campaign will have its ad displayed in a search result.

We’ve seen many instances where companies know PMax doesn’t convert as well as Search, so they might set a CPA of $25 on Search and $50 on PMax. The higher CPA target allows PMax to submit higher bids, increasing its ad rank and likelihood of winning the auction.

This means allocating a sufficient budget to Search and monitoring impression share data is crucial for ensuring Search impressions aren’t lost.

6. Other campaign settings

If your campaign settings make one campaign ineligible to show ads, of course, the other will show ads instead. This is why we’d recommend checking that your campaign settings are consistent between Search and PMax.

The most common inconsistencies are:

• Included locations
• Excluded locations
• Ad scheduling

In this account, the bid strategies, location targeting, and ad schedules vary across campaigns. This makes one campaign ineligible in some locations or at specific times, so that the other campaign serves ads instead. Since also use different, When these campaigns do compete, their bidding strategies use different formulas to calculate bids, causing variations in their ad rank.

Using the same targeting options across campaign types can help ensure your Search campaigns show ads over your PMax campaigns.

7. Misspellings

In June 2024, Google announced that they would combine misspellings with proper spellings in search terms reports.

However, this has created a huge issue with PMax serving ads for misspelled brand names, even when brand exclusions are in place.

One of our advertisers — a large brand with a two-word name — experienced this issue. While we can’t reveal their name, we can use Papa John’s as a comparable example. Despite brand exclusions, the following misspelled search terms were triggered by PMax campaigns:

• Papajohns
• Papa john
• Papa Johns Pizzas
• Papa John Pizza
• Papa Jons
• Johns Papa
• Pizza Papa Johns
• Papa Johns Little Rock

This issue forces advertisers to reconsider older keyword strategies, such as manually adding every possible misspelling as an exact match keyword. Some brands have already adopted this approach to limit PMax stealing brand impressions.

While this workaround is effective, it feels like a step backward. Ideally, Google will address this challenge to provide a more streamlined solution. In the meantime, advertisers should consider experimenting with exact-match misspellings.

Wrap-up

Google will continue expanding PMax’s capabilities and pushing advertisers to implement this campaign type. However, many advertisers are hesitant to adopt PMax — or to try it again if they previously abandoned it — until Google provides more transparent insights into how these campaigns operate. Although PMax launched as a mostly black box system, Google has since provided a few more insights. Still, the extent to which advertisers will embrace it is up in the air.

Excluding Shopping ads, PMax often works well as a backfill system. Advertisers are finding success using Search as their primary inventory source and letting PMax serve ads across non-search channels.

However, letting PMax take over your Search ad serving often leads to poor results. To maximize performance when using both Search and PMax campaigns, you should ensure your Search campaigns serve ads in the search ad slots, while PMax is reserved for non-search inventory.

To give Search the best chance of serving over PMax, follow this checklist:

• Add your top search terms as keywords
• Organize ad groups effectively by aligning relevant ads and keywords
• Do not remove redundant keywords
• Ensure your Search campaigns have enough budget to serve all day. If they do not, then move budget from PMax to Search. (Please note this not does apply to retail feed PMax campaigns)
• Use consistent bid methods, time of day, and location targeting options across Search and PMax

Follow us for more PPC insights and research.