Editing any account or campaign settings, such as bid strategy, budget, conversion goals, audiences, location, language, and ad scheduling can change your performance.
If you’re using Smart Bidding strategies, it takes about 1-2 weeks for the campaign to learn and fully optimize. Any changes to your conversion action settings, selective optimization setting, or attribution model can also impact your campaign’s performance while it adapts and optimizes towards these new settings.
Example
If your actual average CPAs have been around $10 for the past 14 days, suddenly reducing your Target CPA to $2 can cause a drop in serving or fluctuations in performance.
If you need to make changes to your targets to align with your business goals, we recommend making smaller changes and waiting to see the impact, instead of making larger changes.
What you can do
Check change history for updates made to the account or campaign.
Need something else?
Check other common reasons why your campaign performance is fluctuating.