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Imagine you have two different teams in the same store, both offering the same product. One is fast and innovative, leveraging AI to its advantage. The other is more traditional, but proven and reliable. How would you decide which team to send to the customer? That’s exactly the kind of dilemma many advertisers face when they use both Performance Max and standard Shopping campaigns within M.Ads.
Until now, the fast team, in this case, P.Max, always had the upper hand. In situations where both P.Max and standard Shopping campaigns were active within the same account, the system would consistently favor Performance Max in the auction, regardless of its actual performance. The current approach introduces more balance. Campaign selection is no longer determined by the type of campaign but solely by how well it performs at any given moment.
What is campaign overlap and why does it matter?
Campaign overlap occurs when multiple campaigns within the same account target the same products or audience. For example, just envision you are promoting running shoes through a Performance Max campaign, while also running a standard Shopping campaign for the exact same product. Both campaigns share the same goal, promote the same item, and reach similar audiences.
In these cases, the system would automatically prioritize Performance Max. This campaign type uses advanced automation and artificial intelligence, making it a more technically sophisticated format. One of its main advantages was simplicity, as it was always clear which campaign would be shown in the auction.
However, the downside was limited control. Advertisers had no way to test which campaign might perform better in specific situations. For certain products, seasons, or audience segments, a standard Shopping campaign might have delivered stronger results, but the system never had the chance to display it.
Auction based on campaign performance, not campaign type
As of May 2025, Microsoft has updated the auction rules for these campaigns. Performance Max no longer automatically takes priority over standard Shopping campaigns. Instead, the usual auction logic now applies: the campaign with the higher Ad Rank wins.
What does this mean in practice?
- Performance over campaign type.
- More room for testing & optimization.
- Better control of budget & targeting.
What do we recommend?
- Adjust budgets & goals as needed.
- Follow best practices for P.Max.
- Use diagnostics to improve results.
Why Performance Max still deserves your attention?
Performance Max remains the most advanced AI-powered tool in the Microsoft Advertising portfolio. According to data from the US between February and April 2025, Performance Max campaigns drive up to 39 percent higher conversion rates compared to standard Shopping campaigns. That is why it still makes sense to use this format as a powerful ally in acquiring new customers.
Source: Microsoft Advertising
Conclusion
More control means more opportunity…
The change in auction rules between Performance Max and standard Shopping campaigns is a significant update for advertisers. You no longer have to rely blindly on the automatic priority of P.Max, now you can truly test which campaign delivers the best results for your goals.
Campaign overlap is no longer a problem but an opportunity to optimize spend, adjust objectives, and gain better insight into how your ads are performing.
In the end, the equation is simple: more control = better results.
