Meta made Customer Lifecycle Strategy available to all advertisers. You label a campaign as acquisition, and Meta recommends excluding your existing customers from it. Meta is also testing a single audience label, so you can exclude a whole group of existing customers in one go instead of stacking lists.
This matters because broad targeting on Meta loves people who already know you. They click, they convert, and your acquisition campaign looks brilliant while it quietly resells to your own customers. Your cost per new customer ends up far higher than your reports suggest.
We set new-customer and returning-customer goals separately in every account we run. Retention belongs in email and SMS, where it costs far less. Paid acquisition should find people who have never bought.
One catch: Meta only excludes customers it can match. If your customer list in Meta is months old, the exclusion leaks.