Impact of the HEYTEA × FENDI Cobranding Event on Brand Search Volume

Abstract

This study applies an event-study methodology to assess the impact of the HEYTEA × FENDI co-branding campaign launched on May 17, 2023, using daily Baidu Index data for HEYTEA. An estimation window (April 17– May 16, 2023) was used to model expected search trends, and abnormal search volume (ASV) was calculated for the event window (May 17–June 17, 2023). Results show a significant surge in consumer attention: HEYTEA’s index reached 36.9 million on launch day—over 30 times the pre-launch average (t = 3.7058, p = 0.0008). Cumulative abnormal returns (CAR) in the [-1, +1] window reinforced this finding. Social media metrics also reflected strong cross-platform virality, with related Weibo and WeChat hashtags exceeding 240 million views. Drawing on Keller’s customer-based brand equity model and Park et al.’s composite brand alliance theory, the study indicates that luxury–mass co-branding drives short-term brand salience. However, the rapid reversion of search interest to baseline suggests that co-branding primarily boosts visibility rather than building long-term equity. The research provides a replicable framework for measuring consumer reactions to marketing events through search behavior deviations.