Abstract: Danmu function as an augmented commentfeature has been adopted by almost all live streamingplatforms to foster interaction between viewers andthe streamer in China. However, few studies have beenconducted to understand the determinants of users’Danmu sending behavior on live streaming platforms.This study examines this phenomenon from the lens ofeffectance theory and the S-O-R framework. We proposethat two effectances – Danmu effectance and livestreaming effectance – play an essential role in activeDanmu participation. In addition, we explore the effectsof time-enhanced (synchronicity) and space-enhancedtechnical characteristic (visibility) of Danmu on livestreaming platforms on two effectances. Data analysis of877 participations from Douyu platform in mainland Chinaindicates that active Danmu participation is positivelyassociated with Danmu effectance and live streamingeffectance which are influenced by both time-enhancedtechnical feature (synchronicity) and space-enhancedtechnical feature (visibility). In addition, the study findsthat demographic characteristics, namely education andincome, also affect active Danmu participation.

Keywords: Danmu, live streaming, synchronicity, visibility, effectance, active Danmu participation