Customer lists are audiences created by uploading your own database of contacts into an advertising system, where they are matched against the platform's users. This is one of the most effective audiences, because it is based on real customers, not an estimate. It can be used in three ways: to reach existing customers with an offer, to exclude them from acquisition campaigns so that you do not pay for people you already have, and as a basis for finding a similar audience. The match rate tends to be lower than the size of the list, which needs to be taken into account for small databases. Before uploading, check the legal basis for this kind of use and the information given to data subjects – this is processing of personal data for a marketing purpose, and the same rules apply to it as elsewhere.
See also: Audience exclusion, Legal basis for email marketing, RFM segmentation.
