This study investigates the impact of negative emotional appeals in digital marketing, specifically focusing on how emotions of fear and sadness influence the intention to share. Viral marketing utilizes the immense influence of social media to help brand advertisements achieve faster and wider distribution. Previous studies have mainly focused on the effects of positive emotional ad appeals, or have compared the effects of positive versus negative ad appeals on consumer outcomes. Conversely, this study explores how different negative emotions (fear, sadness) differentially influence consumers' intentions to share. This study also explores the mediating role of emotional intensity and the moderating effect of narrative transportation. Through two experimental studies, the findings reveal that high arousal negative appeals (i.e., fear and high-intensity sadness) are more likely to increase sharing intentions among people who are either moderately or deeply engaged with the story in the advertisement, in contrast to low arousal negative appeals (i.e., low-intensity sadness) and positive emotional appeals (i.e., joy). The investigation provides new insight for digital marketing professionals to create compelling advertising content that encourages content sharing.