Definition of 

Ads and Referrals

What's 
Ads and Referrals
: it is one of the possible values for
Traffic Source
. It means:
Users who visited your store listing from an ad or referral and who didn’t have it installed on any other devices at the time. This includes users who installed your app from an ad using the inline install overlay we sometimes show outside of Play Store.

See other fields from

Store Perfomance

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Google Play Console

The (only) data hub made for apps