This means data from your private messaging app feeds into the broader Meta advertising machine, potentially influencing what ads you see on other platforms even if you don't use them.
WhatsApp collects extensive personal data — including your contacts, usage patterns, device identifiers, and location — and shares much of it with Meta and its family of companies, which can be used to target you with advertising on other platforms like Facebook and Instagram. While your actual message content is end-to-end encrypted, significant metadata about your communications is not protected from Meta's data ecosystem. You can submit a data access, deletion, or portability request through WhatsApp's in-app settings under Account > Request Account Info.