By: Jyll Saskin Gales, Google Ads Coach

Ever felt puzzled by fluctuating CPAs in your Google Ads campaigns? It's a common challenge, especially when transitioning between bid strategies. In this post, we'll tackle this head-on, exploring how to choose the right Target CPA when switching from a Maximize Conversions bid strategy.

Understanding the Problem: What is your CPA?

Let's set the stage: You're currently running a Google Ads campaign using the Maximize Conversions bid strategy, aiming to get as many conversions as possible within your set budget. You're considering a switch to Target CPA, where you specify the average cost you're looking to pay for each conversion. However, your CPA data is showing inconsistencies:

• Last 7 days: CPA of $25
• Last 30 days: CPA of $3.50

Which number should you use as your Target CPA when making the switch?

The Google Ads CPA Discrepancy Explained

This discrepancy likely stems from either:

• Significant campaign changes: Perhaps you've made major adjustments to your campaign during the 30-day period, such as adding new keywords, changing ad copy, or targeting a different audience. These changes can impact your CPA and create volatility in your data.
• Low conversion volume: If your campaign has a low number of conversions, even a single conversion can significantly skew your CPA. For example, if you had several conversions early in the month but only one in the last seven days, your 7-day CPA will be much higher than your 30-day CPA.

The 30 and 30 Rule: A Reminder

Remember the golden rule for Smart Bidding in Google Ads: you need at least 30 conversions in 30 days for it to work effectively. This translates to roughly one conversion per day on average. While some fluctuation is normal, aim for relatively stable results before switching to a Target CPA strategy.

Making the Switch: Choosing the Right Target CPA

In general, when transitioning from a Maximize strategy to a Target strategy, use your last 30-day CPA as your Target CPA, or your last 30-day ROAS as your Target ROAS.

However, if your results are volatile, as in the scenario above, your campaign might not be ready for the switch. In this case, I recommend sticking with Maximize Conversions until you achieve more stable results.

Key Takeaways for Setting a Target CPA

• Analyze your data: Before switching bid strategies, carefully examine your CPA data and identify any potential causes for volatility.
• Prioritize stability: Aim for consistent conversion volume and CPA before transitioning to a target CPA strategy.
• Use the 30-day average: When making the switch, set your target CPA based on your last 30-day average CPA.

By following these tips, you'll be better equipped to make informed decisions about your Google Ads bid strategies and optimize your campaigns for success.

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