Because Performance Max campaigns can serve on all of Google’s properties (for example, Google Shopping, Google Images, and YouTube), your campaign may overlap with one or more existing campaigns in your account if they have the same conversion goals, bidding targets, and other settings.
This article explains how Performance Max interacts with other campaigns in your account.
How it works
When a Performance Max campaign overlaps with your other existing campaigns, it will interact with them in the same way other existing campaigns that show ads on that overlapping inventory would interact.
Example
If you add a Display campaign to an account that already has a Display campaign with overlapping settings, Ad Rank will determine which campaign serves the impression to help you achieve a better return on investment (ROI). Assuming these campaigns are in the same account, or the accounts are marked as equivalent (contact support for help with this), the campaigns won’t compete to drive bids higher. Only one campaign will enter the auction to serve an ad.
In the same way, adding a Performance Max campaign to an account with a Display campaign with overlapping settings will cause the campaign with the best ad rank to enter the auction and potentially serve.
A Search campaign with a keyword that exactly matches or is spell-corrected to a person’s query will be preferred over Performance Max. For example, if the search term is "plumbrs", and your account includes the exact match keyword [plumbers] and the broad match keyword plumbrs, then the exact match keyword is preferred. If there are no keywords that exactly match the person’s query across keyword match types, the campaign with the higher Ad Rank will serve. Learn more About keyword prioritization within a Google Ads account.
Like other campaign types, Performance Max campaigns and Standard Shopping campaigns interact according to normal auction dynamics. When both campaign types are in the same account and target the same product inventory, the campaign with the highest Ad Rank will serve.
