What Are Affinity Audiences? How They Work + In-Market Comparison

When setting up a Google Ads campaign, you'll be asked to define your audience. Two of the most useful options are affinity audiences and in-market audiences — and the distinction between them matters more than most advertisers initially realize. Use the wrong one and you'll reach the right people at the wrong moment in their journey, or the wrong people at the right moment.

This guide explains what affinity audiences are, how they differ from in-market audiences, how to build a custom segment when Google's predefined categories are too broad, and how ecommerce brands should use each type.

What Are Affinity Audiences?

Affinity audiences are groups of people who have demonstrated sustained interest in a topic, category, or lifestyle over time. Google builds these audiences by analyzing browsing history, app usage, and other behavioral signals to identify people whose ongoing patterns align with specific interest categories.

Think of affinity audiences as reaching people based on who they are, not what they're actively doing right now. Someone who consistently reads fitness content, follows health brands, and visits nutrition websites will be categorized in fitness-related affinity segments — regardless of whether they're currently shopping for anything.

Google offers hundreds of predefined affinity segments across categories like:

• Banking & Finance
• Beauty & Wellness
• Food & Dining
• Home & Garden
• Lifestyles & Hobbies (including Outdoor Enthusiasts)
• Shoppers (with several sub-segments)
• Sports & Fitness
• Technology
• Travel

A note on naming: in the current Google Ads interface these all sit under Audience segments, where affinity appears as "what their interests and habits are" and in-market as "what they are actively researching or planning." The underlying targeting hasn't changed, but the older "affinity audience" and "in-market audience" labels are now interface descriptions rather than separate products.

What Are In-Market Audiences?

In-market audiences are groups of people who are actively researching and considering purchasing a specific product or service. Google identifies these users based on recent search queries, product comparisons, website visits, and other signals that indicate purchase intent — not just general interest.

The key difference: in-market audiences capture current intent. An in-market segment for running shoes includes people who have been searching for running shoe reviews, comparing prices, and visiting product pages in recent days or weeks. Once they make a purchase, they typically exit the segment.

In-market audiences are lower in the purchase funnel than affinity audiences. They've already moved past general interest into active consideration.

Affinity vs. In-Market: Key Differences

The practical implication: use affinity segments when you're trying to build awareness or reach people who fit your category profile. Use in-market segments when you want to reach people who are actively comparing and close to buying.

Benefits of Affinity Audiences for Ecommerce

For Shopify brands and DTC ecommerce, affinity audiences are most valuable for prospecting campaigns — reaching potential customers who haven't heard of the brand but fit the profile of someone who would be interested in it.

A sustainable outdoor gear brand can target affinity segments around outdoor and eco-conscious lifestyles to introduce the brand to people whose habits align with what it sells. This is more efficient than broad demographic targeting because the interest alignment means higher relevance, even though the person isn't actively shopping yet.

Three other situations where affinity earns its place:

• Video and Display inventory. On YouTube and the Display Network you're reaching people inside their regular content consumption, not mid-search. Interest-based targeting fits that context better than intent-based targeting does.
• New products or new markets. Before there's search volume for what you sell, affinity is often the only way to reach a relevant pool at scale.
• When in-market segments are too small. Some categories generate weak or infrequent purchase-intent signals. Affinity gives you a larger addressable pool where in-market would starve the campaign.

Benefits of In-Market Audiences for Ecommerce

In-market audiences are higher-intent and generally more efficient for direct response campaigns. A Shopify store selling sports equipment can target the relevant sports and fitness equipment in-market segment to reach people who are actively comparing products.

The efficiency comes from the intent signal: these users have already done research, which shortens the decision cycle. In-market segments work particularly well layered onto Search campaigns as an observation or bid-adjustment signal, and on Shopping campaigns, where you can push harder on users already showing purchase intent.

Using Both Together

Affinity and in-market audiences aren't mutually exclusive. A layered approach — affinity for top-of-funnel awareness, in-market for bottom-of-funnel conversion — creates a full-funnel structure that captures customers at different stages of the purchase journey.

For a new brand without significant remarketing lists, this combination is often the most effective way to build reach and conversion efficiency at the same time. Affinity campaigns build familiarity; in-market campaigns capture the people already ready to buy.

Setting Up Affinity and In-Market Audiences in Google Ads

Both are found in the Audiences section when creating or editing a campaign or ad group:

1. Open the campaign or ad group in Google Ads
2. Go to Audiences, keywords and content > Audiences and click to edit
3. Choose Browse, then the interests category to find affinity segments, or the "actively researching or planning" category to find in-market segments
4. Select the segments relevant to your category
5. Choose Targeting or Observation

Targeting mode restricts your ads to people in the selected segment. Observation mode lets ads run normally while Google reports performance for that segment, so you can see how it performs and adjust bids. Observation is the better starting point on almost every campaign: it gathers the data without shrinking your reach. Once you can see which segments convert, tighten toward them with bid adjustments or move to targeting.

Custom Segments: Building Your Own Affinity Audience

When Google's predefined categories are too broad for your niche, you build a custom segment. This is what used to be called a custom affinity audience. Google merged custom affinity and custom intent into a single custom segment type, so you no longer choose between them — you supply the inputs and Google weights them as interest or intent based on the campaign type they're used in.

How to create a custom segment

1. In Google Ads, open Tools, then Shared library > Audience manager
2. Select Custom segments and click the plus icon
3. Name the segment
4. Add your inputs: search terms and interests, URLs of sites your customers visit, and apps they use
5. Save the segment, then apply it to the relevant campaigns or ad groups

Google shows an estimated reach as you add inputs, which is the fastest way to tell whether a segment is too narrow to serve.

Choosing good inputs

Interests and URLs generally do more work than app inputs. A specialist running brand gets a far sharper segment from terms like "trail running," "ultramarathon," and "thru-hiking" plus the URLs of running gear publications than it does from a broad outdoor category. The same logic applies to a boutique fitness brand building around high-intensity interval training rather than generic sports and fitness.

Two input sources worth building into the process:

• Competitor and category publication URLs. Sites your prospective customers already read are strong signals of category interest. Note that this affects who sees your ads, not what your ads say — Google's trademark policy still governs whether competitor names can appear in ad copy.
• Your own placement reports. The "Where ads showed" report tells you which sites and apps actually delivered performance. Feeding proven placements back in as URL inputs is a cheap way to sharpen a segment using your own data rather than guesswork.

Where custom segments apply

Custom segments do the most work on Display, Demand Gen, and YouTube campaigns, where there's no keyword to carry intent. On Search campaigns the keywords already supply the intent signal, so custom segments there are best used in observation to read performance rather than to restrict who sees the ads.

What to Measure

Affinity segments usually reach further and cost less per impression than in-market segments, and usually convert at a lower rate. That's a function of funnel position, not a failure of the targeting — you're reaching people who might be interested rather than people already shopping.

Judge them accordingly. For awareness-focused affinity campaigns, look at reach, frequency, view rate, and downstream assisted conversions over a longer attribution window. For in-market and custom segments applied to conversion campaigns, hold them to cost per acquisition and ROAS. Comparing an affinity prospecting campaign to a branded search campaign on last-click ROAS will always make the affinity campaign look worse than it is.

Over time, the segment-level performance data is worth more than the campaign it came from: it tells you which interests and behaviors actually describe your buyers, which then informs creative, product, and the rest of your media plan. For more on building Shopify ad campaigns, see our guides on ecommerce ad campaigns, brand awareness campaign strategy, and Shopify Audiences.