Lookalike Seeds Select, size, and validate the seed customer list that a lookalike, similar, or value-based audience will be built from. Three principles govern every step below: - Match count, not row count - every uploaded list shrinks by its match rate before it reaches the platform's minimum. A 40% match on 5,000 rows is a 2,000-person seed, and the platform floor applies to that matched number - upload 2-3x the target. - Homogeneity and value concentration beat size - Meta's own guidance holds that a seed's homogeneity affects audience effectiveness more than its size. Practitioner conse…