Towards age-friendly live streaming: the impact of bullet-screen comments speed and density on older adults' user experience in health-oriented live streaming

Purpose This study examines how bullet-screen comment (BSC) speed and density jointly shape older adults' information acquisition, perceived effort and consumer experience in health-oriented live streaming, with implications for platform engagement and health-marketing communication. Design/methodology/approach A 2 (speed: slow vs. fast) × 3 (density: low vs. medium vs. high) between-subjects experiment involved 60 healthy Chinese adults aged 60–65 (n = 10 per condition). Participants viewed a 60-second simulated health stream and completed a ten-item information-acquisition test and five single-item ratings. Two-way ANOVAs assessed main and interaction effects; brief interviews contextualised the quantitative findings. Findings Speed and density interacted for information-acquisition accuracy, willingness to use, and perceived effort. Density significantly affected all subjective outcomes. Low density generally supported more favourable evaluations, whereas medium density produced greater immersion than high density. The predicted universal advantage of slow comments was not supported. Research limitations/implications The small sample, narrow age range, one-minute simulation, single-item subjective indicators and incomplete archival records for absolute comment velocity and exposure limit construct validity and generalisability. Practical implications Platforms should avoid fixed bullet-screen settings. Low density is advisable for information-intensive health content, while speed should be adjusted jointly with density and user preference. Originality/value The study extends digital-inclusion research to dynamic comment overlays in health-oriented live streaming and identifies speed-density interactions and non-linear boundary conditions in older adults' responses.