"Our special price is only once, and then there will be no more" The Language Magic in Live Streams: How Vocal and Semantic Features of Influencers Dynamically Trigger Purchases

Live streaming enables real-time interactive shopping, which makes the streamer's performance crucial for sales. However, the impact of streamers' verbal interactions on consumer decisions hasn't been fully studied. Using the Elaboration Likelihood Model (ELM) and Fear of Missing Out (FOMO) integrated framework, this research explores how streamers' vocal and semantic features affect sales, and how these effects differ among streamer types. We collected data from 552 live streams by 96 popular streamers on the Douyin e-commerce platform from March to May 2025, conducting real-time analysis with multimodal minute-level data. Results show that streamers' vocal and semantic features positively impact sales. Specifically, speech rate and scarcity-creating statements from mid-sized and small streamers have a bigger sales effect, while celebrity streamers rely more on brand effects than verbal skills. This study offers an in-depth view of the differential impact of streamers' verbal features on consumer decisions in live-streaming shopping and gives strategy guidance for industry practitioners.