Recent experiments showed that the valence of user comments (i.e., social information) presented alongside online videos can alter viewers' enjoyment of videos. However, it is unclear how much attention video viewers pay to social information and whether the effects found in previous studies occur if participants are not forced to view the social information. Therefore, this study investigated how the valence of social information presented alongside online videos affects viewers' enjoyment when viewers are free to determine whether and how much attention they pay to social information. Using an eye tracker, we found that most video viewers pay attention to social information which then elicits a valence effect on their enjoyment. Results also showed that a negativity bias occurred: Participants paid most attention to negative social information. Accordingly, the effect of social information on enjoyment was stronger for negative social information. This study is the first to show that social information of online videos affects the experiences of video viewers in settings where viewers are in charge of how much attention they pay to social information.On social media platforms, users are not only exposed to content created by professional content providers, they are also exposed to content created by average users, notably, to evaluative information in the form of comments and (dis)likes. This evaluative information is referred to as social information.