Why is there a discrepancy between the number of customers in Google Ads and the number of 'done' customers in my scenario? 

The "done" status in the Ad Audience node indicates the number of customers successfully matched based on the selected filter attributes. This number represents the number of customers we sent to the Google Ads API. However, it does not reflect the total number of customers added to the Google Ads audience. Google Ads further filters this list to match only emails associated with active Google accounts and other criteria.

What attributes are considered for customers who are being added to the Google Ads Audience?

Email addresses in Engagement must be linked to a Google account to add the customer to the Google Ads audience. Our Ads Audience node cannot determine which customers match a Google account, leading to a higher number of customers in the node than in Google Ads.

Additionally, some Google users have privacy settings that prevent their data from being used for advertising, so their emails won't be matched even if they have a Google account.

We only have data on the number of customers sent to the audience, not on the success of the matching process.

How can the number of customers added to Google Ads be increased?

Using matching rules that include both email and phone numbers can be beneficial. A customer's email address in Engagement might not be linked to a Google account, but their phone number might be. Incorporating phone numbers into the matching criteria increases the likelihood of successfully matching customers to their Google accounts, potentially increasing the overall match rate.

This dual-method strategy leverages multiple data points to improve the accuracy and effectiveness of audience targeting in Google Ads.