How to Use Google Ads Audience Segments the Right Way (Observation vs. Targeting)

How to Add Audiences to Google Ads (Without Sabotaging Your Campaign)

One of the most misunderstood features in Google Ads is audience segments. Most advertisers either ignore them completely—or worse, overuse targeting too early and choke performance before the campaign ever has a chance to learn.

If you want audience data that actually improves results (instead of creating noise), the setup matters. A lot. This guide walks through how to add audiences properly, when to use Observation vs. Targeting, and how to think about audience data like a strategist—not a checkbox-clicker.

First: Your Non-Negotiable Prerequisite (GA4 + Google Ads)

Before you touch audiences in Google Ads, your Google Analytics (GA4) account must be connected to Google Ads. This connection is what unlocks:

Website visitor audiences
Engagement-based segments
Smarter remarketing lists
Accurate cross-platform attribution

Without GA4 connected, you’re flying blind. You’ll still see Google’s default affinity and in-market audiences, but you’ll miss the most valuable data: how real users who touched your site behave inside your ads account. If GA4 isn’t connected yet, stop here and fix that first.

Where to Add Audiences in Google Ads

You can add audiences in two places:

During campaign setup
Later inside the Audiences tab in campaign settings

Functionally, they’re the same. For new campaigns, adding them during setup is fine and often faster. Once inside the Audience Segments section, you’ll see recently used audiences, Google’s suggested ideas, and your first-party GA4 audiences.

Pro tip: I usually enable “Recent + Ideas” so nothing useful is hidden.

The Most Important Decision: Observation vs. Targeting

This is where most advertisers mess up.

Observation (Use This First)

When you add audiences in Observation mode, Google:

Does not restrict traffic
Does not optimize toward those audiences
Only collects performance data

This means one person can belong to multiple audiences, and your impressions are not diluted. Observation is pure intelligence gathering. For new campaigns, this is almost always the right choice.

Targeting (Use Later, With Proof)

Targeting tells Google: “Only show ads to people in these audiences.” That’s powerful—but dangerous if you don’t have data. I don’t recommend targeting at campaign launch, with assumptions, or with small budgets. Targeting makes sense only after you’ve identified audiences that consistently outperform others.

Why You Can Add “Too Many” Audiences (Safely)

In Observation mode, adding more relevant audiences does not hurt performance. A common misconception is that if you have 10 audiences and 10 clicks, each gets one. That’s not how it works. Because users overlap across audiences, you might see 10 clicks total but 40+ audience interactions reported. This overlap is exactly what makes the data valuable.

Example: Audience Selection for a Skydiving Company

If you’re running Google Ads for a skydiving business, relevant audiences might include:

Strong Fits: Travel & vacationers, outdoor enthusiasts, thrill seekers, and adventure lifestyle segments.
Weak Fits: Generic lifestyle audiences or equipment purchasers two steps removed from the service.

Affinity vs. In-Market Audiences

Affinity: Long-term interests (who they are).
In-Market: Recent buying intent (what they’re shopping for).

From a setup standpoint, the distinction matters less than relevance. Select audiences based on whether the data would be useful to analyze later, not because Google labels it as “high intent.”

First-Party Audiences: Your Most Valuable Data

This is where GA4 integration pays off. Always include:

All website visitors
Google Ads visitors
Google Analytics users
Optimized remarketing lists

Sometimes the insight is counterintuitive; you might find that previous visitors convert significantly worse, allowing you to exclude them and improve CPA immediately.

Interest & Habits: Go One Level Deeper

If you have the budget, you can go broad (Sports & Fitness) or narrow (Weightlifters). Layering both helps you identify which specific subset actually drives the needle. This is vital for future segmentation and message customization.

Combined Segments: Skip for Now

Combined segments require manual logic and custom rules. Ignore them until you have performance benchmarks and are ready to engineer audiences rather than explore them.

Key Takeaways

Always connect GA4 to Google Ads first.
Use Observation mode for all new campaigns.
Add multiple relevant audiences without fear of “splitting” traffic.
Avoid targeting until you have clear performance proof.
Audience data is for future decisions, such as bid adjustments, exclusions, and budget reallocation.