Trouble Understanding Google Match Rate vs. Audience Size

The match rate in Google indicates the percentage of the list that Primer sends that Google can match to an associated user they have information on. Since Primer provides a lot of personal emails, and Google has seen many of these emails before, match rates can sometimes be quite high.

However, it's important to note that the match rate only tells us how many users Google can identify, not how many users are available to be served an ad.

What really matters in Google is the actual matched audience size. You will see a significant difference between the stated Google match rate and the available audience sizes for Search, Youtube, Display, etc.

A similar situation occurs on LinkedIn. For example, LinkedIn might report a 90% match rate, but the actual audience size can vary. In some cases, the audience size may even exceed 100% because one email address might be associated with two different LinkedIn profiles.

This discrepancy occurs because the match rate measures identification, while audience size measures the number of users who can actually be targeted with ads.

When we show match rates inside of Primer, we use the actual matched size reported by the ad platform (in this case Google) divide by total number of people synced through to the destination.

        Primer Match Rate = Audience size in google / # of people in Primer audience