By: Jyll Saskin Gales, Google Ads Coach, Inside Google Ads

Reaching the right person at the right time with the right message is a foundational concept in Google Ads. One of the surefire ways to reach the right people is to leverage remarketing - or, as it’s called now in Google Ads, “Your data segments.” Google Ads offers various ways to do remarketing, and one powerful yet relatively new and unknown option is the Google-engaged audience. But how does this audience segment compare to the more widely used Google Ads website-based remarketing list or Google Analytics website-based remarketing list?

What are Google-engaged audiences?

In this excerpt from my bestselling book Inside Google Ads: Everything you need to know about Audience Targeting I explain what engaged audiences are, and why they’re so powerful:

The newest type of Your data segment in Google Ads is called Engaged audiences. This segment type is such an elegant solution to a complicated problem, it brought a genuine smile to my face when I first started seeing Engaged audiences pop up in my clients’ accounts.

Engaged audiences let you reach users who have previously interacted with your website on Google Search, YouTube, Maps, and other Google properties. Every Google Ads account automatically gets one Engaged audience segment, and this segment will automatically populate with users who have visited your site from Google properties, through either ads or organic search result clicks. No account linking or audience setup necessary!

What makes Engaged audiences special?

• Ease of use. Unlike every other type of remarketing, you don’t need to do anything. No Google tag. No account linking. No data uploads. An Engaged audience segment will magically appear in your Google Ads account, and you can use it with just a few clicks.

• Simplicity. Every Google Ads account gets one Engaged audience, and this segment will include everyone who visited your website from your Google Ads on Google-owned properties, and from organic search results on Google. While I’m sure people are already complaining about this “limitation,” wishing for landing page segmentation and property segmentation, I view this as a “feature” - Engaged audiences exist to help small business owners, and small business owners don’t need more bells and whistles.
• First-party data. Since Engaged audiences populate with users who are on a Google-owned property, and then click to your website, Google knows exactly who those users are. As with YouTube-based remarketing segments, these are mostly signed-in users, so audience quality is high and there’s no need to pass data back and forth. 

This is what makes Engaged audiences such an elegant solution. Google is already tracking when people click from an ad to your website. Rather than waiting until they land on your website, and then tracking them through cookies or some other technology you need to implement and maintain, Google is now capturing their information before they leave Google Search, YouTube, etc. - and since these sites are all part of Google’s ecosystem, Google takes care of user consent and tracking, and you now have an easy-to-use remarketing solution.

The challenge with Engaged audiences is that it’s only tracking people who clicked on your ads or search results. Depending on your budget and overall marketing strategy, this may be a small portion of your total website visitors. If you’re also running Meta Ads, for example, people who visit your website from Meta Ads would not be tracked by your Google Engaged audience. If you have a lot of direct traffic, or organic social media traffic, or referral traffic, those website visitors would not be included on your Engaged audience segment either.

Purpose of this study

A PPC Marketing specialist named Christoph Gummersbach asked me on LinkedIn “How does the size of Google-engaged audiences compare to traditional tag-based remarketing lists in your experience?”

I chose this question to answer in Episode 72 of my Inside Google Ads podcast about “Audience Failures,” and then realized I didn’t know the answer yet… and I needed to find out.

Methodology

I examined 14 different Google Ads accounts, comparing the size of their Google-engaged audiences to two other standard remarketing lists: the "All Visitors" list from the Google Ads tag, and the standard "All Users" list from Google Analytics 4 (GA4). I chose these because almost every Google Ads account has at least one, if not both, of these lists in their Audience Manager.

To make fair comparisons for a general overview, I used a method called indexing. For each advertiser, on each network (Search, YouTube, and Gmail), I set the Google-engaged audience size at 100 and then adjusted the other audience sizes accordingly. This helps us see the relative sizes of these audience segments in a clear and understandable way. I did not include Display, since Google-engaged audiences are not compatible with Display.

To give you a better sense of the accounts I analyzed, here are the actual largest and smallest Google-engaged audience sizes observed, not indexed:

• Largest Google-Engaged Audiences:
• Search: 11,000,000
• YouTube: 10,000,000
• Gmail: 7,000,000
• Smallest Google-Engaged Audiences:
• Search: 4,700
• YouTube: 4,600
• Gmail: 3,100

Results

My analysis revealed some interesting patterns across these remarketing audiences.

a) Comparative Audience Sizes by Source: Google Ads, GA4, Google-Engaged

The Google Analytics (GA4) audience was generally a bit larger than the Google-engaged audience:

• For Search, it was 28% larger on average and 8% larger on median than the Google-engaged audience.
• For YouTube, it was 46% larger on average and 9% larger on median than the Google-engaged audience.
• For Gmail, it was 10% smaller on average and 9% smaller on median than the Google-engaged audience.

The Google Ads audience was significantly smaller than the Google-engaged audience:

• For Search, it was 62% smaller on average and 80% smaller on median than the Google-engaged audience.
• For YouTube, it was 61% smaller on average and 80% smaller on median than the Google-engaged audience.
• For Gmail, it was 90% smaller on average and 93% smaller on median than the Google-engaged audience.

Out of the 14 accounts analyzed, just one had Google Ads audience sizes that were larger than the Google-engaged audience sizes. For this advertiser, the difference on Search was 2.7x, and on YouTube 2.9x. However, on Gmail, the Google Ads audience was still half the size of the Google-engaged audience.

Here is a closer look at the differences between Google Analytics and Google-engaged audience sizes:

• 6 advertisers had Google Analytics audiences that were larger than their Google-engaged audiences, in line with the overall trend. 5 were lead generation businesses, 1 was an ecommerce business. They were a mix of small, medium and large budget advertisers. 
• The advertiser with the largest difference has a Google Analytics audience size that’s 3.4x larger on Search, 4.5x larger on YouTube, and 2x larger on Gmail than the Google-engaged audience. This advertiser did not have Google Ads audiences implemented.
• 5 advertisers had Google Analytics audiences that were smaller than their Google-engaged audiences. These were a mix of small and large advertisers, ecommerce and lead gen. 
• Two advertisers in the data set had Google-engaged audiences that were approximately 10x larger than their Google Ads or Google Analytics audiences. These were outliers compared to the rest of the data set, but the fact that there were two of them suggests this is not as rare an occurrence as one might expect. Both advertisers are B2B SaaS companies, but they operate in different industries, with different target audiences, different budgets, different ads strategies and different levels of brand awareness (one is large, one is small). One reason could be that both of these businesses are heavily reliant on Google for their website traffic. I would love to study this further to determine the factors that contribute to a very large Google-engaged audience.
• 1 advertiser had Google Analytics audiences that were about the same size as their Google-engaged audiences. 
• 2 advertisers did not have Google Analytics audiences imported into their Google Ads account

b) Comparative Audience Sizes by Network: Search, YouTube, Gmail

I was intrigued by how much smaller the Gmail audience sizes were versus the Search and YouTube audiences, across all three data sources. To explore this finding further, I re-indexed the data to set the Gmail audience size at 100 and then adjusted the other audience sizes accordingly.

The Gmail audience was much smaller than the Search and YouTube audiences:

• For Google Ads audiences, Search and YouTube were 420% larger on average and 400% larger on median than Gmail.
• For Google Analytics audiences, Search was 128% larger on average and 123% larger on median than Gmail, while YouTube was 233% larger on average and 133% larger on median than Gmail.
• For Google-engaged audiences, Search was 74% larger on average and 59% larger on median than Gmail, while YouTube was 83% larger on average and 54% larger on median than Gmail.

The discrepancy was largest with the Google Ads remarketing audience, where Search and YouTube had audience sizes that were about 4x larger than Gmail. The discrepancy was smaller with Google Analytics audiences, where Search and YouTube had audience sizes that were 2x-3x larger than Gmail. The discrepancy was smallest with Google-engaged audiences, where Search and YouTube had audience sizes that were not even twice as large as Gmail.

Out of the 14 accounts analyzed, none had a Search audience size or YouTube audience size that was smaller than its Gmail audience size, for any of the data sources.

I acknowledge a key limitation of this study is the small sample size of 14 Google Ads accounts. While these accounts encompass a mix of ecommerce and lead generation objectives, and a range of budgets and brand sophistication, it is possible that these findings are skewed or potentially not applicable at scale. I welcome the opportunity to collaborate with others in the industry to expand this research across 100+ accounts.

Key Takeaways

Based on the results of this study, here's what we've learned about Google-engaged audiences and Gmail audiences:

• Google-engaged audiences are similarly sized to Google Analytics, with different makeup: On networks like Search and YouTube, Google-engaged audiences are generally a similar size to Google Analytics 4 (GA4) audiences. While Google-engaged audiences don't include direct website traffic, visitors from other websites (referral traffic), or traffic from social media platforms, they do capture both paid and organic interactions from Google-owned properties like Google Search, YouTube and Maps.
• Tag-based audiences are suffering: In contrast, I found that both Google-engaged audiences and Google Analytics audiences are generally much larger than the standard "All Visitors (Google Ads)" audiences. This highlights the limitations of relying solely on the Google Ads tag for remarketing in 2025 and beyond, as it appears to miss out on vast numbers of users.
• It’s harder to reach users on Gmail: Performance Max and Demand Gen campaigns let you place ads on Gmail. This analysis revealed that Gmail-eligible audience sizes tend to be much smaller than those for Search and YouTube. Intuitively, this makes sense; even though all of these Google products have more than 2 billion monthly active users, usage patterns for Google Search and YouTube are undoubtedly higher and more frequent than for Gmail. However, the “Gmail dropoff” was less pronounced with the Google-engaged audience across all accounts analyzed, likely because it's powered by Google’s own signed-in user data.

What This Means for You

Building on these findings, here's what these results mean for your Google Ads strategy:

1. Don't overlook Google-engaged audiences: Given their ease of use, automatic setup, and surprisingly robust size relative to basic Google Ads remarketing lists, Google-engaged audiences are a highly efficient and valuable tool. They represent a pre-qualified segment of users who have actively engaged with your site through Google's own ecosystem, making them ideal for re-engagement campaigns. However, Google-engaged audiences are not compatible with the Google Display Network, which means you can’t use them in a Display campaign, they won’t work on Display inventory in a Search, Demand Gen or Video campaign, and their “signal capabilities” will be limited in Performance Max and App campaigns. If GDN inventory makes up at least 10% of your Google Ads investment, keep this in mind if you’d like to start leveraging your Google-engaged audience.
2. Complement Google-engaged with GA4 for broader reach: While Google-engaged audiences are powerful, my findings suggest that GA4 audiences often offer a wider reach, capturing traffic from non-Google sources like direct visits or social media. For advertisers seeking the broadest possible remarketing pool, combining Google-engaged audiences with GA4-based lists would provide the most comprehensive strategy to reach users who have interacted with your brand. Given the rise of AI tools, this comprehensiveness is an immense value add.
3. Rethink sole reliance on tag-based Google Ads remarketing: The significant size disparity between Google Ads "All Visitors" lists and both Google-engaged and GA4 audiences highlights a critical point: relying solely on the standard Google Ads remarketing tag for audience building in 2025 is likely to result in missed opportunities. This runs counter to the standard advice that I and many Google Ads Experts give - that audience building via the Google tag is superior to audience building via Google Analytics. I would love for those with broader and deeper account access than me to further study these discrepancies. It could be due to implementation issues, challenges with consent mode, cookie loss through non-Chrome browsers, etc.
4. Always use Google-engaged for Gmail remarketing: The observed differences in audience size across Search, YouTube, and Gmail underscore the importance of considering platform-specific audience dynamics. If you’re running Demand Gen campaigns with a remarketing objective, be sure to include the Google-engaged audience in your audience targeting. If you’re running Performance Max campaigns, be sure to include the Google-engaged audience in your audience signal. 

In conclusion, Google-engaged audiences have distinct benefits for all advertisers. They might not always be the largest audience, but their direct connection to Google’s own first-party data makes them especially powerful for remarketing strategies, reaching users on Gmail, and expanding your reach in light of declining website traffic due to AI Overviews, AI Mode, ChatGPT, and other AI tools.

Further reading

Book - Inside Google Ads: Everything you need to know about Audience Targeting

Article - Google-Engaged Audiences: Your Secret Weapon for Google Ads Remarketing