The use of social network sites (SNSs) has grown dramatically. Numerous studies have shown that SNS users may suffer from excessive use, associated with addictive-like symptoms. With a focus on the popular SNS Facebook (FB), our aims in the current study were twofold: First, to explore the heterogeneity of FB usage and determine which kind of FB activity predicts problematic usage; second, to test whether specific impulsivity facets predict problematic use of FB. To this end, a sample of FB users (N = 676) completed an online survey assessing usage preferences (e.g., types of activities performed), symptoms of problematic FB use and impulsivity traits. Results indicated that specific usage preferences (updating one's status, gaming via FB, and using notifications) and impulsive traits (positive and negative urgency, lack of perseverance) are associated to problematic FB use. This study underscores that labels such as FB "addiction" are misleading and that focusing on the actual activities performed on SNSs is crucial when considering dysfunctional usage. Furthermore, this study clarified the role of impulsivity in problematic FB use by building on a theoretically driven model of impulsivity that assumes its multidimensional nature. The current findings have identifiable theoretical and public health implications.