Lookalike audiences can help you reach audiences that share commonalities with your existing customers, and deliver your ads to audiences who are interested in your product.
There are three lookalike audience size options (Narrow, Balanced, and Broad), which provide flexibility based on your distinct marketing strategies.
Creating a Broad lookalike audience increases potential reach with moderate similarity between the lookalike audience and the source audience. Creating a Narrow lookalike audience helps find users who have the highest level of similarity with your source audience, but the size of the audience in a Narrow lookalike audience will be relatively smaller than a Broad/Balanced lookalike audience.
The size of the lookalike audience is based on the user base of the market you specified and the scale you selected (Narrow, Balanced, and Broad). The minimum size of the source audience for lookalike creation is 1000.
The model will use algorithms to study the attributes of the custom audience you create and look for users who are similar with potential to improve performance.
Visit Create a Lookalike Audience to learn more.