Custom Audiences are a tailored targeting feature that enables advertisers to create audiences of known or engaged users using a file upload, website or app activity, TikTok engagement, or an audience activation partner.
There is a requirement to have 1,000 total matched users in a Custom Audience to use it in an ad group.
Custom audiences can be used for:
Retargeting leads or past engagers, moving them towards conversion
Optimizing campaign spend by excluding recent customers
Creating lookalike audiences for prospecting
There are several ways to create a Custom Audience:
Challenge
Premium Audience
The 'Available Audience' size estimator on the campaign creation step will display a more realistic reach of the campaign using a custom audience. The 'Available Audience' is based on a number of factors including the user's opt-in status, age and location, among others. To read more, visit Audience Size Estimation Overview