Detailed definition
You upload your existing customer list (with hashed email addresses) to Meta or Google, and the platform generates a pool of similar users. A 1% lookalike: the closest match (a small pool, high conversion). A 5-10% lookalike: broader, but less similar. It is the best approach to cold audiences in e-commerce and SaaS, and one of the most effective ways to reduce CAC.
Examples
- An existing list of 500 customers → a 1% lookalike → 50K+ similar users.