The source – support.google.com
Google started showing match rate when uploading email addresses to your account – the percentage of the audience from the list to which you can run ads right now.
Previously, you had to wait to get this data. Additionally, the Google Ads Help says that the system will show match ratios for listings uploaded from January 1, 2020.
To improve your match rate, Google recommends adding as much customer information as possible. According to the company's internal data, advertisers who downloaded two types of customer information increased the average list size by 28%, while those who downloaded three types increased by 35%.
You can also improve your match rate by fixing formatting issues and working with third-party e-list download services. But match rate is not a measure of the effectiveness of lists.
Reaching more audiences will help you keep your customer lists updated on a regular basis. So Google started showing an advice to update the listings on the recommendation page.
Outdated data limits the amount of information for audience searches. According to Google internal data, after updating the listings, traffic and conversions increase by an average of 17%.