If you have set up GA4 tracking with Growth Hub, every visit to your storefront already generates data: who viewed a space, who started checkout, and who submitted a booking request but didn't pay. That data is the foundation for retargeting, and most operators never use it.

Retargeting lets you show ads to visitors as they browse the web, reminding them to return and complete a booking. Because these are people who have already visited your site and shown commercial intent, they convert at a much higher rate than cold advertising audiences.

This set of articles walks you through the full process, from building the right audiences in GA4 to launching and monitoring your first campaign in Google Ads.

Prerequisites

This guide assumes your Growth Hub GA4 tracking is already set up and events are flowing into GA4. If it is not, complete that setup first.

GA4 is implemented through the Growth Hub GTM container.
Growth Hub events are visible in GA4, including view_item, begin_checkout, add_to_cart, purchase, and generate_lead.
A Google Ads account is linked to your GA4 property.
Ad creative assets (images, headlines, descriptions) are ready before launching a campaign.

Not set up yet? Complete the GA4 and GTM setup first. Google Analytics (GA4) tracking for Growth Hub →

Overview of the process

The process is covered in 4 articles, including the current one. Each article covers a distinct stage. Read them in order the first time. Return to individual articles when you need them later.

	Article	What it covers	When you need it
Overview	This article	Overview of the full process and how the 3 setup articles connect	Start here
1	Build retargeting audiences in GA4 →	Create audiences from Growth Hub events in GA4. Link GA4 to Google Ads and enable audience sharing.	One-time setup before any campaign
2	Launch a Google Ads retargeting campaign →	Choose campaign type, prepare assets, configure, and launch your first Display campaign in Google Ads.	When audiences are ready and sized
3	Monitor and troubleshoot your campaign →	What to watch in the first 14 days, how to diagnose common issues, and how to build your reporting view.	After launch, ongoing

How the process stages connect

The 3 setup articles follow a fixed dependency chain. Skipping ahead causes problems that are hard to diagnose later.

Building audiences must come first. Audiences are built from GA4 events and must exist before a campaign can use them. Google Ads cannot target audiences that have not been created and shared in GA4. Build retargeting audiences in GA4 →
Audiences need time to build. GA4 audiences only accumulate users from the moment they are created. They do not backfill historical data. A new audience for begin_checkout may take days or weeks to reach the minimum size Google requires before ads start serving. This is why Article 1 should be done as early as possible.
Launching a campaign assumes audiences are ready. Do not launch a campaign until your audiences have enough users. Google requires at least 100 active users in the last 30 days for Display campaigns to serve. Launch a Google Ads retargeting campaign →
Monitor and troubleshoot early. Set up your reporting view when you launch, not after. You need to be watching from day 1 to catch issues early.

The most common mistake: Creating audiences and launching a campaign on the same day. The audience has 0 users at that point. The campaign is running but serving no impressions. Build audiences first, wait for them to populate, then launch.

The Growth Hub events that power retargeting

Growth Hub sends the following events to GA4. Each one can be used to build a retargeting audience based on where a visitor dropped off in your booking funnel.

Event	What it means	Retargeting use
`view_item`	Visitor viewed a space or resource	Broad consideration audience. Largest pool.
`add_to_cart`	Visitor added a booking to cart	Mid-funnel intent audience
`begin_checkout`	Visitor started the checkout flow	High-intent audience. Strongest for retargeting.
`add_payment_info`	Visitor entered payment details	Highest-intent. Very narrow pool.
`purchase`	Visitor completed a booking	Use as exclusion to avoid targeting existing customers.
`generate_lead`	Visitor submitted a booking request	Works well for follow-up after inquiries.

Recommended starting point

For most operators running their first retargeting campaign, start with 2 audiences and 1 campaign.

Audience 1: view_item, exclude purchase. Membership duration 30 days. This is your broadest audience and builds fastest.
Audience 2: begin_checkout, exclude purchase. Membership duration 7 to 14 days. This is your highest-intent audience and should receive your strongest message.
1 Display campaign. Target the begin_checkout audience first. Switch to view_item if the audience is too small to serve.

Once this is working, expand to a second campaign for view_item and later consider adding generate_lead as a 3rd audience.

Retarget Your Growth Hub Visitors with Google Ads (Overview)