Google's ready-made audiences are a good start, but they're broad. A segment like "Fitness Enthusiasts" can include everyone from a marathon runner to someone who watched one workout video. Custom segments fix that. They let you describe your ideal customer yourself, using the words they search, the websites they visit, and the apps they use.
Used well, custom segments are one of the most precise audience tools in Google Ads. Used poorly, they burn budget on people who were never going to buy. Here's how they work and how to build them the right way, whether you sell products online, software to businesses, or services in your local area.
What Is a Custom Segment?
A custom segment is an audience you create by giving Google signals about who you want to reach. Google then finds people whose activity matches those signals. You build a segment from three kinds of inputs:
- Keywords: words and phrases that describe your customer's interests, behaviors, or what they're shopping for.
- Websites: URLs of sites your ideal customer is likely to visit. Google reaches people who browse websites similar to the ones you enter.
- Apps: apps your ideal customer is likely to use. Google reaches people who use apps similar to the ones you enter.
One common misunderstanding: adding a competitor's website does not mean your ads appear on that website. It tells Google what kind of person you're looking for, and Google finds people with similar browsing behavior.
Interests vs. Search Terms: The Most Important Setting
When you add keywords to a custom segment, Google asks how it should use them. There are two options:
- People with any of these interests or purchase intentions (the default). Google treats your keywords as topics and looks for people who seem interested in them.
- People who searched for any of these terms on Google properties. Google looks for people who actually typed those searches on Google. This option applies on campaigns running on Google properties. Everywhere else, your keywords are treated as interests.
For most advertisers, the search-term option is the stronger choice when the goal is sales or leads. Someone who searched "best CRM for small teams" or "waterproof hiking boots" last week is far more valuable than someone Google thinks is generally interested in the topic. Search intent is the closest thing to a raised hand.
Where You Can Use Custom Segments
Custom segments work in these campaign types:
- YouTube (Video) campaigns: show video ads to people who recently searched for what you sell.
- Demand Gen campaigns: reach people across YouTube, Discover, and Gmail.
- Display campaigns: reach people across websites and apps in Google's Display Network.
- Performance Max: custom segments can't be applied directly as targeting, but you can add them as an audience signal to guide Google's AI toward the right people.
Custom segments aren't available as audience targeting in standard Search or Shopping campaigns. On Search, your keywords already do this job.
How to Create a Custom Segment
- In Google Ads, open Audience manager (under Tools, or use the search bar at the top of the account).
- Go to Segments, click the plus button, and choose New custom segment.
- Give it a clear name, like "Project management software searchers," so you know what it is months from now.
- Choose whether to target people by interests or by what they searched on Google.
- Add your keywords. Optionally, expand the segment with websites and apps.
- Save it, then add it to an ad group, or to a Performance Max asset group as an audience signal.
New segments can take a little time to build. Check back after a day or two to see the estimated audience size.
Examples by Business Type
Ecommerce store selling outdoor gear
- Type: People who searched for any of these terms on Google
- Search terms: best hiking boots, waterproof hiking boots, lightweight backpacking tent, trail running shoes review
- Websites: competitor stores and popular gear review sites
B2B software company
- Type: People who searched for any of these terms on Google
- Search terms: project management software, asana alternatives, best tool for team task tracking, project management software pricing
- Websites: competitor product and pricing pages, software comparison sites
Local service business
- Type: People who searched for any of these terms on Google
- Search terms: dentist accepting new patients, teeth whitening cost, invisalign near me
- Websites: competitor practices and local review sites
Everyone in these segments has shown real buying intent recently. A short video showing your product, a free trial offer, or a new-customer special lands very differently with this group than with a broad interest audience.
Tips for Better Custom Segments
- Keep each segment tightly themed. One product line, service, or buying intent per segment. "Running shoes" and "camping tents" should be separate segments.
- Use buyer language, not industry jargon. Your customers search "best CRM for small teams," not "customer relationship management platform."
- Favor specific phrases over single words. "Shoes" is too broad. "Trail running shoes for wide feet" says exactly who you want.
- Add competitor URLs. People browsing your competitors are actively comparing options.
- Test segments against each other. Put different segments in separate ad groups so you can see which one produces sales or leads at the best cost.
- Judge by cost per conversion, not clicks. This only works if your conversion tracking is set up correctly.
Common Mistakes to Avoid
- Mixing unrelated themes in one segment, which muddies who Google goes after.
- Leaving the setting on "interests" when you meant to target recent searchers.
- Expecting custom segments to work as targeting in Search campaigns.
- Turning a segment off after a few days. Give it enough time and spend to produce real conversion data before deciding.
Final Thoughts
Custom segments let you describe your best customer in your own words instead of settling for Google's broad categories. For any business running YouTube, Demand Gen, Display, or Performance Max, search-term segments are often the fastest way to put your ads in front of people who are ready to buy.
At Uppertier Marketing, we build custom segments around how your customers actually search, then measure them against real sales and leads, not just clicks. If you'd like a second set of eyes on your audiences, schedule a call with our team.
