Google Analytics 4 (GA4)
Google's current analytics platform, which measures website and app activity as events and replaced Universal Analytics in July 2023.
GA4 is the default source of traffic, conversion and channel data for most websites, and its key events can feed Google Ads bidding, so setup quality affects both reporting and media performance.
A store installs GA4 through Google Tag Manager, sends purchase events with transaction ID, value and items, marks purchase and generate_lead as key events, tags campaigns with UTM parameters and links the property to Google Ads and BigQuery.
GA4 data is affected by consent choices, ad blockers and data thresholds, and modeled data fills some gaps, so totals rarely match CRM or ecommerce records. Standard properties have retention and export limits, and metrics differ from Universal Analytics.
GA4 records every interaction as an event with parameters and groups events into users and sessions. Data arrives from the Google tag, Firebase SDKs or the Measurement Protocol, and Server-Side Tracking can route it through a tagging server. Consent Mode adjusts collection and enables modeling. The BigQuery export delivers raw, unsampled daily event tables, capped at 1 million events per day for standard properties, plus an optional streaming export. Campaign data relies on Urchin Tracking Module (UTM) parameters.
Performance Advertising
Google Analytics Help — Introducing the next generation of Google Analytics — https://support.google.com/analytics/answer/10089681; Google Analytics Help — BigQuery Export — https://support.google.com/analytics/answer/9358801
