Google this month announced it has updated the campaign measurement in Google Analytics 4, in compliance with Apple’s policies.
According to Google, the Google click identifier (GCLID) is no longer used without user consent in iOS14+. For these cases, Google Ads introduced two new URL parameters for app to app measurement - GBRAID - and for app to web measurement - WBRAID.
Google says reporting on affected traffic will use modeled conversions, and advertisers can see the Impacted traffic reported as source/medium = google/cpc. Additional Google Ads dimensions (including Campaign) will be reported as (not set).
Google states advertisers can continue to import Analytics conversions into Google Ads from both Universal Analytics properties and Google Analytics 4 properties.