Custom Audiences
Advertising audiences built from an advertiser's own data — customer lists, website visitors, app users, or engagement data — used for retargeting and as seed audiences for lookalikes on Meta, Google, and LinkedIn.
What Types of Custom Audiences Exist on Meta?
Meta supports four primary Custom Audience types. Customer List audiences are built from uploaded email addresses, phone numbers, or other identifiers matched against Meta’s user base — typical match rates range from 30% to 70%. Website Custom Audiences target users who visited specific pages on your website, tracked via Meta Pixel or Conversions API. App Activity audiences target users based on in-app events. Engagement audiences target users who interacted with your Meta content (watched a video, opened a lead form, engaged with an Instagram profile). Each type serves a different stage of the funnel: customer lists for retention, website audiences for retargeting, and engagement audiences for warming up interested prospects.
How Do Custom Audiences Work on Google and LinkedIn?
Google Ads calls them Customer Match (for uploaded lists) and Remarketing Lists (for website visitors). Customer Match allows advertisers to upload email lists that Google matches against signed-in users across Search, Shopping, YouTube, Gmail, and Display. Match rates on Google typically range from 40% to 60%. LinkedIn offers Matched Audiences with three varieties: Company targeting (upload a list of company names or domains), Contact targeting (upload email lists), and Retargeting (website visitors via the LinkedIn Insight Tag). LinkedIn’s professional data makes its company-level targeting uniquely powerful for B2B campaigns — advertisers can target decision-makers at specific companies with tailored messaging.
How Are Custom Audiences Affected by Privacy Changes?
Privacy changes since iOS 14.5 have significantly impacted Custom Audience capabilities. Apple’s App Tracking Transparency reduced Meta Pixel tracking accuracy, shrinking website Custom Audiences and reducing match quality. Meta’s Conversions API (CAPI) was introduced to compensate by sending conversion data server-side, bypassing browser-level tracking restrictions. Customer list audiences are less affected by privacy changes because they rely on first-party data (direct customer information) rather than cookie-based tracking. Google’s phase-out of third-party cookies in Chrome continues to shift the value toward first-party data, making customer list audiences increasingly important across all platforms.
How Do AI Tools Manage Custom Audiences Across Platforms?
Managing Custom Audiences across Meta, Google, and LinkedIn manually requires uploading and refreshing lists on each platform separately, maintaining segment definitions in three different interfaces, and ensuring consistent audience strategies. AI advertising platforms like Leo automate this process — creating and managing Custom Audiences across all connected platforms from a single interface. Leo can build pixel-based website audiences, manage customer list uploads, and create retargeting segments that stay synchronized across platforms. This ensures that a user who converts via Google Search is excluded from Meta retargeting campaigns in near real time, preventing wasted spend on already-converted customers.