Troubleshooting for Conversion Optimizer

You may encounter some of the following problems or limitations when using Conversion Optimizer:

Can't enable Conversion Optimizer:
The Conversion Optimizer relies on historical data collected through Google Ads Conversion Tracking, so it isn't available for new campaigns, campaigns that just started using conversion tracking, or campaigns that have received fewer than 15 conversions in the last 30 days.

Actual cost-per-acquisition (CPA) is higher or lower than target CPA:
Your actual CPA depends on factors outside of Google's control, so it may be higher or lower than the target CPA you set. The Conversion Optimizer uses historical conversion data to predict the likelihood your ads will convert. However, your actual conversion rate can be affected by changes to your website and ads, or external factors such as increased competition. If your actual conversion rate turns out to be higher or lower than the predicted conversion rate, your actual CPA may differ from your target CPA.

If your average CPA is higher than you prefer, you can lower your target CPA, which will likely decrease both average CPA and the number of conversions. Conversely, you can raise your target CPA if you want to increase traffic and conversions.

Traffic rate decreases after enabling Conversion Optimizer:
If you notice a drop in traffic after turning on the Conversion Optimizer, it's likely that the initial target CPA was too low. Setting a low target CPA is equivalent to decreasing the original CPC bids; it can result in lower position and less traffic on your ads. For this reason, it's best to use the recommended CPA provided when you begin to use the Conversion Optimizer. This target CPA is calculated to help ensure a smooth transition to your new bid strategy. Also, since the Conversion Optimizer aims to get you more conversions by avoiding traffic that doesn't result in conversions, you may see a decrease in impressions or clicks while increasing the number of conversions.

Conversion rate decreases after enabling Conversion Optimizer:
It's possible to see a drop in conversion rate when you start using Conversion Optimizer because you're observing an average of the conversion rate across all clicks. For example, suppose the Conversion Optimizer causes your campaign to have an increase in very cheap clicks with slightly lower conversion rates. If there were no other changes in your campaign, this change would appear as a decrease. However, the change in cost could have a very positive effect on your campaign profit.

Compatibility with other Google Ads features, the search and Display Network, and third-party ads:
The following Google Ads features are not compatible with the Conversion Optimizer:

  • Separate Display Network bids (the Conversion Optimizer will automatically optimize your bids across the search and Display Networks.)
  • Advanced ad scheduling (basic ad scheduling is supported.)

The Conversion Optimizer does work on the search and Display Networks and with third-party ads. (Note that Google Ads Conversion Tracking is still required in order to use the Conversion Optimizer with third-party ads.)

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