This paper studies how an emerging online interaction feature, bullet screen comments, affects viewership and viewer experience of live streaming eSports games. And we further compare its effects on eSports live games and on other eSports videos. Our results reveal that social interaction created through bullet screen comments always improves live streaming viewership and viewer experience, with its impact on viewership being stronger. Moreover, social interaction plays a greater role in live game viewership than on other eSports videos.