What You Will Learn
- How Google builds and maintains its audience segments
- In-Market Audiences — users actively researching purchase categories
- Affinity Audiences — long-term interest-based audiences
- Custom Segments — building audiences from search terms and URLs
- Similar Segments — expanding to lookalike audiences
- Demographic and Life Event targeting
- How to layer multiple audience signals for more precise targeting
How Google Builds Audience Segments
Google builds audience segments from signals collected across its properties: Search queries, YouTube watch history, websites visited (via Google ad tags and the Chrome browser), app usage (Android), Gmail activity, and Google Maps usage. These signals are used to classify users into segments representing their interests, purchase intentions, life stages, and demographic characteristics.
| Audience Type | Signal Basis | Recency | Best Use |
|---|---|---|---|
| In-Market | Recent search and page visit behaviour suggesting active purchase research | Short-term (days to weeks) | Bottom-funnel prospecting |
| Affinity | Long-term interest patterns from content consumption | Long-term (months) | Top-funnel brand awareness |
| Custom Segments | Specified search terms, URLs, or app usage | Configurable | Mid and bottom funnel — intent-specific |
| Similar Segments | Behavioural similarity to your first-party data | Based on source list | Prospecting lookalike audiences |
| Demographics | Demographic signals (age, gender, income) | Profile-based | Demographic qualification layer |
| Life Events | Signals suggesting major life transitions | Event-triggered | Timing-sensitive products/services |
In-Market Audiences
In-Market Audiences consist of users Google has identified as actively researching a specific product or service category based on recent search queries, page visits, and conversion data across the Google network. The "in-market" classification means Google has determined the user is in an active buying cycle — not just generally interested in a topic.
In-Market segments are Google-defined — you select from a taxonomy of categories (Auto > Vehicles > Cars > Sedans; Finance > Banking > Personal Loans; etc.). Categories update in real-time as users' behaviour shifts — a user who searches for running shoes multiple times over three days enters the "Athletic & Outdoor Apparel > Athletic Footwear" in-market segment.
In-Market Audiences are among the highest-performing display targeting options for bottom-funnel campaigns because they specifically target users in active purchase consideration. They work both on Display campaigns and as observation layers on Search campaigns (for bid adjustment without narrowing reach).
Affinity Audiences
Affinity Audiences represent users' long-term interests and lifestyle patterns — people who consistently consume content about specific topics over months. Unlike In-Market (active purchase intent), Affinity reflects sustained interest without necessarily indicating immediate purchase intent.
Google's Affinity categories include broad lifestyle segments: "Outdoor Enthusiasts", "Health & Fitness Buffs", "Technophiles", "Business Professionals", "Foodies". These are suitable for brand awareness campaigns reaching audiences with general relevance to your product or service, but they cast a wider net than In-Market for efficiency-focused campaigns.
Custom Affinity
Custom Affinity allows you to define your own interest-based audience by providing keywords and URLs that represent the lifestyle. Google builds a custom segment of users who follow content similar to the provided examples. More specific than standard Affinity but less intent-focused than Custom Segments.
Custom Segments
Custom Segments are the most flexible and powerful Google Ads audience type for performance-focused campaigns. You define the segment by specifying: people who searched for specific terms on Google, people who visited specific URLs, or people who used specific apps. Google then identifies users matching these criteria across the GDN.
Custom Segments by search terms
Entering search terms creates an audience of users who have recently searched for those terms. This effectively brings search intent signals into display targeting — showing display ads to users who recently searched for "running shoes" gives you reach beyond just the moment of the search query.
Custom Segments by URL
Entering competitor URLs, category page URLs, or informational resource URLs creates an audience of users who visit those types of pages. Entering competitors' websites targets users who are researching your competitors — potentially comparative shoppers at a high purchase-intent stage.
Similar Segments
Similar Segments (formerly Similar Audiences) identify new users who share behavioural characteristics with users in your first-party lists (your site visitors, converters, or customer match lists). They function as lookalike audiences — allowing you to scale prospecting beyond remarketing to new users likely to behave like your existing customers.
Similar Segments are automatically generated by Google from your remarketing lists — they appear in the Audience Manager when your lists are large enough for similarity modelling (typically 1,000+ users). You cannot manually configure similarity parameters — Google determines the similarity model automatically.
Demographics
Demographic targeting reaches users based on age (18–24, 25–34, 35–44, 45–54, 55–64, 65+), gender (Male, Female, Unknown), parental status (Parent, Not a parent, Unknown), and household income (Top 10%, 11–20%, 21–30%, 31–40%, 41–50%, Lower 50%) — the income targeting is available in select countries.
Demographics are best used as qualification layers added to other targeting rather than as standalone audience types. Applying demographic exclusions or bid modifiers to an In-Market audience (e.g. excluding the 18–24 age group for retirement planning products) refines targeting without over-narrowing reach the way demographic-only targeting would.
Life Events
Life Events targeting reaches users in major life transition moments: graduating from university, getting married, moving home, having a baby, starting a new job, retiring, or experiencing bereavement. Google identifies these transitions from search patterns, YouTube behaviour, and other signals.
Life Events are particularly valuable for products and services tied to specific life stages: wedding vendors during "getting married", home insurance and movers during "moving home", baby products during "having a baby", financial planning during "retiring". The timing advantage — reaching the customer when they are most likely to need your service — makes Life Events one of the highest-intent audience types despite lower volumes than standard In-Market segments.
Combining Audiences
Audience combinations (Audience Manager > Combined Audiences) allow you to build segments using AND, OR, and NOT logic across multiple audience types. Examples:
- AND combination (narrowing): In-Market: Running Shoes AND Age: 25–44 — reaches users in the running shoe buying cycle who are in the prime demographic for your brand
- OR combination (broadening): Custom Segment: searched competitor terms OR Remarketing: visited product pages — captures both competitive researchers and prior visitors
- NOT exclusion: In-Market: Running Shoes NOT Remarketing: existing customers — prospecting new customers while excluding those who already purchased
Authentic Sources
Overview of all Google Ads audience types and how they work.
Creating and using Custom Segments from search terms and URLs.