When creating a lookalike audience, what happens to the similarity and reach as the percentage used increases?

When creating a lookalike audience, the percentage represents the degree of similarity to your source audience, such as existing customers. As the percentage increases, the similarity to the source audience decreases, but the potential reach expands. A 1% lookalike audience is the most similar to your source audience, resulting in a smaller, highly targeted group. A 10% lookalike audience will be less similar, but significantly larger, offering a broader reach. For instance, if your source audience is comprised of high-value customers, a 1% lookalike will target those most resembling them, while a 10% lookalike will target a larger but less precisely defined group of potential customers who share some characteristics with your high-value base. Therefore, a higher percentage sacrifices similarity for increased reach.