Measurement & Tracking
GA4 Key Events
Key events are the events in Google Analytics 4 that you mark as important business outcomes; they replaced the term conversions in GA4 and can be imported into Google Ads as conversion actions.
In practice
GA4 collects events, from page views to purchases. Marking an event as a key event tells Analytics to report it as an outcome and makes it available to link into Google Ads. Google renamed conversions to key events in GA4 to reduce confusion with Google Ads conversions, which have their own attribution logic.
That distinction matters in practice. A GA4 key event imported into Google Ads is attributed using GA4's model and its cross-channel view; a native Google Ads conversion tag is attributed to the last Google Ads click. Importing both for the same outcome double counts. We generally use native Google Ads tags for the events that drive bidding and keep GA4 key events as secondary observations, or the reverse for accounts where GA4 is the single source of truth, but never both as primary.
GA4 also needs its own hygiene: enhanced measurement can create noisy events, and the purchase event must carry value and currency to be useful in Ads.
Why it matters
They are the bridge between Analytics and Ads, and mishandling that bridge double counts conversions.
RELATED TERMS
Conversion Action
A conversion action is a defined event in Google Ads (purchase, form submission, call, sign-up) that the account counts as a valuable outcome and that Smart Bidding optimizes toward when set as primary.
Google Tag Manager (GTM)
Google Tag Manager is a free tag management system that deploys and controls marketing and analytics tags on a website from a single container without editing site code for each change.
Attribution Model
An attribution model is the rule set that decides how credit for a conversion is divided among the ad interactions that preceded it, such as last click, first click, or data-driven.
Written by Ilya Bulychev, Founder, Live PPC Ads. Part of the PPC Glossary.
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