What Is a Custom Audience? Definition, Sources and How It's Used
A custom audience is an ad-platform audience built from people who already have a relationship with you, such as website visitors, app users, customers on an uploaded list or people who engaged with your content, so you can show them ads directly or exclude them.
Platforms such as Meta, Google and LinkedIn let you create audiences from first-party data. Typical sources are: visitors tracked by a pixel or tag, a customer or email list you upload for matching, app activity, and engagement with your videos, posts or lead forms. Names and requirements differ by platform, for example Customer Match on Google. [NEEDS VERIFICATION: confirm current platform names, matching rules and minimum list sizes.]
Custom audiences have three main uses. Retargeting people who visited but did not buy (see what-is-retargeting); excluding existing customers from acquisition ads so you do not pay to reach them; and seeding a lookalike audience, which finds new people resembling the source (see what-is-a-lookalike-audience). Source quality matters, since a list of your best customers makes a better seed than all site visitors.
Privacy and consent are part of the picture. Uploading personal data requires that you collected it lawfully, and platforms require you to confirm that. Browser and operating-system privacy changes have reduced how much visitor tracking is available, so audience sizes can be smaller than expected. Very small audiences may also not be eligible for delivery.
Why it matters
Infinall AI does not build, upload or manage audiences, install tracking, or place ads; audience setup and targeting happen in your ad platform, and consent and privacy compliance are yours to handle. What Infinall does is produce the creative and copy you would show those audiences: from a product URL it drafts research, strategy, ad copy and creative, which land in an Approval Queue for you to edit and approve before export. A reasonable pattern is distinct messages for people who know you and for those who do not, since a custom audience of past visitors responds to different copy than a cold one.
Related terms
Frequently asked questions
What can I use to build a custom audience?
Common sources are website visitors tracked through a pixel or tag, a customer list you upload, app users, and people who engaged with your video, page or lead forms. Which sources are available depends on the platform and on the tracking you have installed.
Is a custom audience the same as a lookalike audience?
No. A custom audience is made of people you already have data on. A lookalike audience is a new group the platform builds to resemble a source audience, often a custom one. Lookalikes reach people who have not yet interacted with you.