Troubleshooting Performance Max spend fluctuations

In this article, we’ll outline different reasons for Performance Max campaign fluctuations and changes, why they may lead to changes in campaign performance over time, and how you can use the tools in your Google Ads account to understand the cause and effect of these changes.

Before you begin

Use Explanations to identify reasons for performance changes in a single click

Explanations give you insights into large changes in your Performance Max campaign’s performance and help you quickly find out why the changes occurred. By default, you’ll have Explanations that compare the date range you selected with the previous period of the same length. Here’s how to review Explanations:

1. In your Google Ads account, go to your Campaigns or Ad groups page.
2. Hover over values in your data table that are colored in blue with a dotted line.
3. You’ll notice how this value has changed since the last period.
4. Click View explanation to learn what caused the change.

Assess performance based on your bid strategy and optimization goal

Before making conclusions about your campaign performance, it’s important to first consider whether the settings you’re using align with the metrics that your campaign is optimizing towards. Updating your campaign’s bid strategy or optimization goal settings to align with your business and advertising goals will help to ensure that you’re focusing on the relevant metrics when analyzing campaign performance to understand what caused the fluctuations.

For example, Target CPA helps you get as many conversions as possible at or below the target cost-per-action (CPA) you set. In campaigns that use Target CPA, cost-per-conversion and other conversion-related metrics may be better indicators of performance than cost-per-click and impressions.