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.

Bear in mind

It’s normal for your campaign performance to vary.

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:

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

Assess performance based on your bid strategy and optimisation 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 optimising towards. Updating your campaign’s bid strategy or optimisation goal settings to align with your business and advertising goals will help to ensure that you’re focusing on the relevant metrics when analysing 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.

Experiencing fluctuations in spend?SpikeDrop

Which bid strategy do you use to achieve your goals?I use Maximise conversions with target CPAI use Maximise conversionsI use Maximise conversion value with target ROASI use Maximise conversion value

What is the actual CPA that your campaign is achieving?I notice a spend increase and find that my bid strategy shows that Actual CPA is within close range of my target CPA over two weeks or two conversion cycles (whichever is longer) excluding the conversion lag period.I notice a spend increase and find that my bid strategy shows that the Actual CPA is not within close range of the target CPA over two weeks or two conversion cycles ending on the day of increase.

What other details do you notice?You observe conversion delays during the time period when a spend increased.You made relevant changes to the campaign or account within days of spend spike and/or the day of spend spike (before the spike).Account-level policy or billing issue

What changes did you make?BudgetBid strategy, target, seasonality adjustment or data exclusionConversion setting at account or campaign or attribution modelCampaign settings (automatically created assets, location targeting, language targeting, ad schedule or new customer acquisition setting, page feeds and more)Assets or asset groupsLinked accounts (Google Merchant Center, Hotel Centre or Google Business Profile)