What do you need prior to creating a lookalike audience in Campaign Manager?

To create a lookalike audience in Campaign Manager, you first need a source audience. This source can be an uploaded contact list (e.g., customer emails) or a website audience (based on visitors tracked by the LinkedIn Insight Tag). LinkedIn uses the characteristics of this source audience to find new users with similar attributes, expanding your reach to potentially interested prospects. Without a foundational audience to analyze, LinkedIn cannot generate a lookalike. A live campaign running for 60 days is not a prerequisite; lookalike audiences can be created and used in new campaigns. While Audience Expansion is a related feature for broadening reach, it's distinct from the foundational requirement for creating a lookalike audience itself.