<p>This study investigates the effectiveness of sponsorship in live sports events broadcasted through Social Live Streaming Services (SLSSs). Drawing on the limited capacity model, an experiment with 10 hypothetical stimuli was conducted to investigate the impacts of live chat (“no chat,” “informational chat,” and “emotional chat”), streamer presence (“without streamer” and “with streamer”), and game suspense (“low” and “high”) on brand recognition. The findings reveal that informational chat, streamer presence, and game suspense negatively influence brand recognition, implying that sponsor messages receive lower priority when viewers are engaged in multiple secondary tasks in SLSSs. This research contributes theoretically by enhancing understanding of how viewers allocate to sponsoring brands in the multi-information environment of SLSSs. Practically, the study suggests marketers strategically optimize brand exposure by targeting less suspenseful moments, fostering emotional engagement among co-viewers, and leveraging streamers’ ability to draw attention, such as through brand mentions. Furthermore, it is recommended to increase the prioritization of sponsor messages within SLSSs by enhancing the relevance of sponsor messages to the primary task (sport viewing) or individuals.</p>