Prior research on predictors of social network site (SNS) use has mainly focused on the Big Five, narcissism, and self-esteem. Results have been inconsistent, and variance explained was rather low. Need for popularity (NfP) might be a better predictor of SNS use, because SNSs are ideal venues for people with a high NfP. Study 1 tested NfP, self-esteem, need to belong, entitlement, and vanity as predictors for a range of SNS behaviors; Study 2 replaced entitlement and vanity with narcissism and added the Big Five as predictors. SNS behaviors assessed were grooming, strategic self-presentation, profile enhancement, disclosure of feelings, routine use of SNS, and number of friends. Results showed that NfP was the strongest and most consistent predictor of SNS behaviors. This pattern indicates that NfP plays an important role in SNSs. © 2012 Mary Ann Liebert, Inc.