Troubleshooting Performance Max spend fluctuations

This article outlines different reasons for Performance Max campaign fluctuations and changes. It explains 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. Go to Campaigns or Ad groups page within the Campaigns menu .
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. Select 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 can indicate performance better than cost-per-click and impressions.

Check for market trends and shifts in user interest

Performance fluctuations, like budget overspend or underspend, sometimes result from external market shifts rather than major campaign settings. You can utilize Google Trends to analyze if specific search terms or products have experienced a sudden surge or decline in user interest and traffic.

Here's how to address overspending or underspending due to market shifts:

• To correct overspending driven by a demand spike:
  • Implement negative keywords to block inefficient traffic.
  • Adjust bid targets.
  • Tighten budget caps.
• To correct underspending if interest drops:
  • Broaden keyword targeting.
  • Expand audiences.
  • Shift budget toward other trending terms or products capturing active market demand.