GA4 audiences for remarketing are considerably more powerful than Universal Analytics remarketing lists, but that power comes with configuration complexity that trips up most marketers. Poorly configured audiences lead to lists that never populate, targeting that is too broad to be profitable, or lists that exclude users who should be in them because of subtle logic errors. This guide covers the configuration details that the GA4 documentation glosses over.

The Audience Builder Logic Model

GA4’s audience builder evaluates users against three types of conditions: event-based conditions (the user triggered a specific event), parameter-based conditions (a specific event had a parameter with a certain value), and user attribute conditions (first touch source, device category, age bracket, etc.). Within each condition group you can combine multiple conditions with AND or OR logic. Across condition groups, you combine with AND.

The critical nuance is the “within same event” toggle. When you add a parameter condition alongside an event condition, you must decide whether the parameter must be present in the same event or whether it can appear in any event at any time. For an e-commerce audience targeting users who viewed a specific product category, you want the page_location parameter within the same view_item event. Without enabling “within same event”, a user who viewed any product and also had a page_location parameter set in any event in their history will qualify.

Audience Membership Duration

Every GA4 audience has a membership duration setting that controls how long a user stays in the audience after qualifying. The default is 30 days and the maximum is 540 days. For cart abandonment audiences, 3–7 days is appropriate because cart intent decays quickly. For a past purchaser audience used for upsell campaigns, 180–540 days makes sense. Leaving all audiences at the 30-day default is a mistake that silently destroys remarketing ROI.

Scope: User, Session, and Event

When you add an event condition to a GA4 audience, you must choose the scope: user, session, or event. User scope asks “has this user ever triggered this event.” Session scope asks “did this user trigger this event in the session where another condition was also met.” Event scope asks “did all these conditions occur in the same single event.” For most remarketing purposes, user scope over a defined time window is appropriate.

Building a Cart Abandoner Audience Correctly

A properly configured cart abandoner audience has three components: Include users who triggered add_to_cart (at any time in the membership window), Exclude users who triggered purchase (at any time in the membership window), and set membership duration to 7 days. The exclusion condition is critical — without it, your cart abandoner audience will include users who already completed a purchase, wasting impressions on converted users.

In GA4’s audience builder, add the inclusion condition first (add_to_cart event), then click Add condition group with the NOT operator to add the exclusion (purchase event). Verify the logic reads correctly in the audience preview before saving.

Predictive Audiences

GA4 offers predictive audiences for properties that meet eligibility criteria: at least 1,000 returning users per week with purchase events and at least 1,000 non-purchasing users per week. Eligible properties can create audiences for “likely 7-day purchasers”, “likely 7-day churners”, and “predicted 28-day top spenders” without writing any custom conditions. If predictive audiences do not appear, check that your purchase events include a value parameter with non-zero revenue — the predictive model requires revenue data to function.

Audience Triggers

GA4’s audience triggers feature fires a new event when a user joins an audience. This event can be used as a conversion goal, creating a remarketing-ready conversion action that fires when high-intent users first qualify rather than when they complete a purchase. A practical use case: create a “high-value prospect” audience for users who viewed pricing three or more times without purchasing, then add an audience trigger that fires when a user enters this audience. Import this event as a Google Ads conversion action to help campaigns optimize for high-intent users earlier in the funnel.

Linking GA4 Audiences to Google Ads

GA4 audiences are available in Google Ads only after you link the GA4 property in Admin → Product Links → Google Ads Links. After linking, audiences take 24–48 hours to appear in Google Ads. GA4 audiences are retroactive for up to 30 days — when you create an audience, GA4 backdates membership using historical event data. An audience you create today can immediately populate with users from the past 30 days who met the qualification criteria, giving you a head start on audience size before your campaigns launch.