Results of multiple regression analyses indicate that social identification with the Facebook profile owner and ingroup vs outgroup perception moderate the influence of consumers’ materialism, fashion involvement and opinion leadership on interpersonal attraction to the celebrity, wishful identification with the celebrity, emotional quotient, involvement with the ads, advertising believability and willingness to buy the advertised fashion products. Furthermore, the results of structural equation modeling analyses show that source credibility perception (both the celebrity who endorses her own brand and the Facebook profile owner) mediates the relationship between experimental conditions (celebrity as aspirational outgroup vs same school student as an ingroup member vs different school student as an outgroup member) and the outcome variables (interpersonal attraction to the celebrity, involvement with ads, and advertising believability) in viral marketing leveraging a social media platform.