Affinity Audiences & In-Market Audiences: The Complete Google Ads Guide

Affinity audiences are one of Google's core audience targeting types. They let you reach people based on their long-term interests, habits, and lifestyles — not just what they're searching for right now. This guide explains what affinity audiences are, how they work, how they differ from in-market audiences, and how to use both effectively in Google Ads campaigns.

What Are Affinity Audiences?

Affinity audiences are groups of users that Google has classified based on demonstrated long-term interests. Google builds these segments by analyzing users' browsing history, search behavior, app usage, and location data over time. If someone consistently reads cooking blogs, watches cooking videos, and searches for recipes, Google classifies them as part of the "Cooking Enthusiasts" affinity segment.

The key distinction is that affinity audiences reflect who someone is — their ongoing interests and identity. This is different from in-market audiences, which reflect what someone is actively shopping for right now.

Google offers hundreds of predefined affinity categories including:

• Banking & Finance
• Beauty & Wellness
• Food & Dining
• Home & Garden
• Outdoor Enthusiasts
• Shoppers (various sub-segments)
• Sports & Fitness
• Technology
• Travel

Affinity Audiences vs. In-Market Audiences

These two targeting types are frequently confused but serve different purposes in the funnel.

The practical implication: use affinity audiences when you're trying to build brand awareness or reach people who might be interested in your category. Use in-market audiences when you want to reach people who are actively comparing and about to buy.

What Are Custom Affinity Audiences?

Custom affinity audiences let you build your own audience segment rather than relying on Google's predefined categories. You define the audience by combining:

• Interests — keywords or phrases that describe what your ideal customer is interested in
• URLs — websites your ideal customer visits (competitors, industry publications, related blogs)
• Places — types of physical locations your audience frequents
• Apps — apps your audience uses

For example, an outdoor apparel brand might build a custom affinity audience using keywords like "trail running," "ultramarathon," and "thru-hiking," combined with URLs of running gear publications and apps like AllTrails or Strava. This produces a much more specific audience than the generic "Outdoor Enthusiasts" predefined category.

Custom affinity audiences are available in Display, YouTube, and Discovery campaigns. They're not available for Search campaigns (which already use keyword targeting).

How to Set Up Affinity Audiences in Google Ads

1. In Google Ads, navigate to your campaign or ad group
2. Click Audiences in the left menu
3. Click the pencil icon to edit audiences
4. Select Browse and choose Affinity & detailed demographics
5. Browse Google's predefined affinity categories and select relevant segments
6. Optionally, scroll to Custom segments to create a custom affinity audience
7. Choose Targeting (ads only show to this audience) or Observation (ads show to everyone, but you can monitor and bid-adjust for this audience)

For most new campaigns, start with Observation mode. This lets you collect performance data on the audience segment without restricting your reach. Once you have enough data to see which segments perform best, you can switch to Targeting mode or apply bid adjustments.

When to Use Affinity Audiences for Ecommerce

Affinity audiences work best in specific ecommerce scenarios:

Brand awareness campaigns. If you're launching a new product or entering a new market, affinity audiences help you reach people who are likely to be interested before they're actively searching. This is particularly effective on YouTube and Display, where you can reach people in their regular content consumption rather than mid-search.

Prospecting for top-of-funnel traffic. Affinity audiences combined with lookalike signals can extend your reach beyond remarketing lists to find net-new potential customers who share characteristics with your best buyers.

Seasonal or category campaigns. Targeting the "Avid Investors" or "Luxury Shoppers" affinity segments for a relevant product category can significantly improve the efficiency of display spend compared to contextual-only targeting.

When in-market audiences are too narrow. In-market audiences for some product categories are small because purchase intent is rare or hard to signal through search behavior. Affinity audiences give you a larger addressable pool for these categories.

Affinity Audience Performance Benchmarks

Affinity audiences typically perform better than broad run-of-network targeting but are generally less efficient than in-market audiences on a cost-per-conversion basis. This reflects their funnel position — you're reaching people who might be interested, not people who are actively shopping. Expect:

• Higher reach and impression volume than in-market
• Lower CTR than in-market (less purchase intent)
• Lower CPM than in-market (less competition for the segment)
• Longer attribution windows needed to measure full value

The right benchmark depends heavily on your category and campaign objective. For awareness-focused campaigns, measure reach, frequency, and brand lift rather than direct ROAS.