Supporting information

Adolescents are particularly vulnerable to social media marketing in the digital age. This experimental study assessed how three types of sponsorship disclosure (full, partial, none) affect 3,149 Taiwanese adolescents' advertising recognition, literacy, and purchase intentions. Full disclosure significantly improved ad recognition and conceptual literacy, while attitudinal literacy was associated with lower purchase intentions. These findings highlight that clear sponsorship disclosure is essential for enhancing adolescent advertising literacy and protecting them from marketing influence.