Add or Exclude Audience Segments in Google Ads

Targeting restricts your ads to only show to users in the selected audience segment — narrowing your reach but increasing relevance. Observation keeps your full existing reach unchanged but lets you collect performance data for that segment and apply bid adjustments. Start with observation to gather data before committing to targeting.

Yes. You can add as many audience segments as you need within a single campaign or ad group. When using Targeting mode, Google will show your ads to users who match any of the selected segments (OR logic). This gives you flexibility to layer different audience types such as remarketing lists, customer lists, and in-market segments together.

Google Ads supports several audience types: Your data segments (website visitors, customer lists, app users), Custom segments (based on search behaviour or interests), In-market segments (users actively researching a product), Affinity segments (long-term interests), Detailed demographics (life events, education, etc.), and Combined segments (audience combinations you build).

Apply at the campaign level when you want the same audience targeting across all ad groups, which is simpler to manage. Use ad group level when different ad groups need different audience strategies — for example, one ad group targeting new users and another targeting past visitors with tailored messaging. Ad group settings override campaign-level settings.

Excluding audiences prevents your ads from showing to people who are unlikely to convert or who you don't want to target. Common exclusions include existing customers (if you only want new customers), recent converters (to avoid showing the same ad after a purchase), or specific demographic groups that historically underperform. Exclusions help improve efficiency and reduce wasted spend.

Yes — switching from observation to targeting will limit your reach to only matched users. If your audience segments are small, this can significantly reduce traffic. For Search campaigns especially, it is generally recommended to start with observation mode to collect data and apply bid adjustments first, then only switch to targeting once you've confirmed the segment performs well and is large enough to sustain your goals.