Google has revised its guidance for Performance Max campaigns, requiring at least 15 conversions over 30 days to achieve stable performance. This new benchmark replaces previous guidance and aims to provide clearer expectations for advertisers managing small campaigns.
The updated Google help page highlights that meeting this threshold is crucial for consistent spend and strong ROAS. During periods of delayed conversion data processing, campaigns may experience spend spikes or low ROAS, but the system can still stabilize and recover.

Additionally, the troubleshooting guidance now advises advertisers to check Channel Prioritization settings when a channel isn’t serving. This includes ensuring channels aren’t set to low priority or have inadequate budget allocations.
Read the official help page here: Troubleshoot performance fluctuations and changes in Performance Max campaigns.
This update was spotted by Hana Kobzová.