Someone visits your website, looks at a product, and leaves without buying. With remarketing, your Google Ads follow them around the web — on YouTube, Gmail, news sites, and across Google’s Display Network — reminding them to come back.
Remarketing typically converts at 2-4x the rate of cold traffic because you’re targeting people who already expressed interest. They know your brand. They’ve seen your product. They just need a nudge.
Here’s how to set it up properly.
The Two Ways to Build Remarketing Audiences
Option 1: Google Ads Tag (Direct)
Google Ads has its own remarketing tag that you place on your website. It builds audiences directly within Google Ads based on which pages people visit.
Pros: Simple setup, audiences are immediately available in Google Ads. Cons: Limited segmentation options, separate from your analytics data.
Option 2: GA4 Audiences (Recommended)
Create audiences in GA4 based on user behavior, then share them with Google Ads. This is the better approach because GA4 has far more powerful audience building tools — you can segment by events, user properties, sequences, and conditions that the Google Ads tag can’t handle.
Pros: Much more granular targeting, audiences based on your full analytics data, single source of truth. Cons: Requires GA4 and Google Ads to be linked.
We’ll focus on Option 2 because it gives you more control and better audiences.
Step 1: Link GA4 to Google Ads
If you haven’t done this already:
- Open GA4 and go to Admin
- Under Product links, click Google Ads links
- Click Link
- Select your Google Ads account
- Enable Personalized advertising (required for remarketing audiences)
- Click Submit
This connection allows GA4 audiences to flow into Google Ads and allows Google Ads conversion data to flow into GA4 reports.
Important: The link works with the Google Ads account, not individual campaigns. Once linked, all GA4 audiences you create will be available across all campaigns in that account.
Step 2: Build Your GA4 Audiences
Go to GA4, then Admin, then Audiences. Click New audience.
Here are the audiences every business should create for remarketing:
All Visitors (7 Days)
Configuration: Include users when session_start event occurs. Set membership duration to 7 days.
Why: These are your hottest prospects. They visited in the last week and your brand is fresh in their mind. This audience gets the highest remarketing priority and the highest bids.
All Visitors (30 Days)
Configuration: Include users when session_start event occurs. Set membership duration to 30 days.
Why: Broader remarketing pool. Used when the 7-day audience is too small to generate meaningful impressions.
Product Viewers (Non-Purchasers)
Configuration: Include users who triggered view_item event. Exclude users who triggered purchase event. Set membership duration to 14 days.
Why: People who looked at specific products but didn’t buy. These are high-intent users. Show them the products they viewed.
Cart Abandoners
Configuration: Include users who triggered add_to_cart event. Exclude users who triggered purchase event. Set membership duration to 7 days.
Why: The highest-intent remarketing audience. They were ready to buy. Show them the product with a compelling reason to come back (free shipping, limited stock, social proof).
Past Purchasers
Configuration: Include users who triggered purchase event. Set membership duration to 90-540 days (depending on your purchase cycle).
Why: Two uses. First, exclude them from acquisition campaigns so you’re not paying to re-acquire existing customers. Second, target them with cross-sell and upsell campaigns.
High-Value Visitors
Configuration: Include users who triggered session_start event AND visited more than 3 pages. Set membership duration to 14 days.
Why: Multi-page visitors showed strong engagement. They explored. They’re more likely to convert than someone who bounced after one page.
For more audience ideas and advanced configurations, see our GA4 audiences and remarketing lists guide.
Step 3: Wait for Audiences to Populate
After creating audiences in GA4, they begin populating immediately with new qualifying users. It typically takes 24-48 hours for audiences to appear in Google Ads.
Minimum audience size: Google Ads requires at least 100 users in an audience for Display campaigns and at least 1,000 for Search campaigns. If your site doesn’t get much traffic, it may take days or weeks for audiences to reach these thresholds.
Step 4: Create a Remarketing Campaign in Google Ads
Display Remarketing Campaign
This shows image and text ads across Google’s Display Network (millions of websites, YouTube, Gmail).
- In Google Ads, click New campaign
- Choose your objective (Sales or Leads)
- Select Display as campaign type
- Under Audiences, click Browse then Your data segments
- Select the GA4 audiences you want to target
- Set your budget (start at $10-20/day for testing)
- Create your ad creative (responsive display ads with multiple headlines, descriptions, and images)
Search Remarketing (RLSA)
Remarketing Lists for Search Ads (RLSA) adjusts your search campaigns for people who’ve visited your site before. When a past visitor searches for your keywords, you can bid higher or show different ad copy.
- Open an existing search campaign
- Go to Audiences and click the edit icon
- Add your GA4 remarketing audiences
- Choose Observation (bid adjustments) or Targeting (only show to this audience)
- Set bid adjustments (e.g., +30% for past visitors, +50% for cart abandoners)
Observation mode is usually best for RLSA. It keeps your ads showing to everyone who searches your keywords, but lets you bid more aggressively for past visitors who are more likely to convert.
Step 5: Set Up Conversion Tracking
Your remarketing campaigns need conversion tracking to optimize properly. If Google Ads can’t see which clicks lead to purchases, it can’t adjust bids or targeting.
Make sure you have:
- Google Ads conversion tag firing on your purchase/thank-you page
- Conversion Linker tag firing on all pages (connects ad clicks to conversions)
- Enhanced conversions enabled for better match rates
See our Google Ads conversion tracking setup guide for the full walkthrough.
Remarketing Best Practices
Frequency Cap Your Ads
Nobody wants to see the same ad 50 times a day. Set a frequency cap of 3-5 impressions per user per day for display campaigns. Go to your campaign settings and look for “Frequency capping.”
Without a cap, you’ll annoy potential customers and waste budget on excessive impressions that don’t generate additional conversions.
Use Different Messaging for Different Audiences
Don’t show the same generic ad to everyone:
| Audience | Messaging Strategy |
|---|---|
| Product viewers | ”Still thinking about [product]?” with product image |
| Cart abandoners | ”You left something behind” + urgency or incentive |
| Past purchasers | ”New arrivals you might like” or “Complete the set” |
| General visitors | Brand awareness + value proposition |
Set Appropriate Duration Windows
| Audience | Recommended Duration | Why |
|---|---|---|
| Cart abandoners | 7 days | Intent fades fast |
| Product viewers | 14 days | Medium consideration window |
| General visitors | 30 days | Broad recall window |
| Past purchasers (for upsell) | 60-90 days | Time to need more |
Exclude Converters
Once someone purchases, stop showing them the “come back and buy” remarketing ad. Add your purchaser audience as an exclusion to all remarketing campaigns. Then create a separate post-purchase campaign with different messaging if you want to target them for repeat business.
Common Mistakes
Not Linking GA4 to Google Ads
If the accounts aren’t linked, your GA4 audiences won’t appear in Google Ads. This is the most basic setup step and it’s missed surprisingly often.
Audiences Too Small
If your website gets 500 visitors a month, a “cart abandoners, last 7 days” audience might have 10 people in it. That’s too small for Google to serve ads to. Start with broader audiences (all visitors, 30 days) and narrow down as traffic grows.
No Ecommerce Tracking in GA4
To build audiences based on product views, add-to-carts, and purchases, those events need to be tracked in GA4. If you only have basic page view tracking, your audience options are limited to page URL rules.
Bidding Too High on Display Remarketing
Display remarketing CPCs are typically much lower than search CPCs ($0.50-2 vs $1-10+). If you set aggressive bids, you’ll spend your budget quickly without proportionally better results. Start with conservative bids and increase based on performance.
Running Only Display, Not RLSA
Display remarketing gets all the attention, but RLSA can be more powerful. When a past visitor actively searches for your product again, that’s extremely high intent. Bidding higher for these users in your search campaigns often has a better ROI than display remarketing.
Measuring Success
Track these metrics for your remarketing campaigns:
| Metric | Benchmark (Display) | Benchmark (RLSA) |
|---|---|---|
| CTR | 0.5-1.5% | 3-8% (higher than cold search) |
| CPC | $0.30-2.00 | Similar to regular search |
| Conversion rate | 0.5-3% | 2-5x your cold search rate |
| ROAS | 3-10x | 4-15x |
Remarketing should consistently outperform your prospecting campaigns. If it doesn’t, check your audience configuration, ad creative, and conversion tracking.
The Bottom Line
Remarketing is one of the highest-ROI advertising tactics available. You’re targeting people who already know you, using the most powerful audience builder (GA4), on the largest ad network (Google). The setup takes an afternoon. The payoff is ongoing.
But it all starts with proper tracking. If GA4 doesn’t know who visited your site, what they viewed, and what they bought, your remarketing audiences will be empty or incomplete.
Run a free scan to check your GA4 and Google Ads tracking setup. We’ll verify that your event tracking, audience configuration, and conversion tracking are all working correctly.