TikTok has emerged as the fastest-growing social media among Generation Z. Despite its widespread popularity, TikTok remains empirically understudied, with most research to date focusing on China. As TikTok’s user base expands globally, this study addresses this gap by collecting data across three countries. Given the variability and inconsistency in responses, Grey Relational Analysis (GRA) was employed. Notably, this study is among the first to examine the adoption of a social media using GRA. This study not only highlights the effectiveness of GRA in analyzing complex data but also deepens our understanding of social media usage across diverse cultural contexts.