This study investigated the extent to which the perceived usefulness, perceived ease of use, perceived enjoyment and social influence of smartphones affected word of mouth, as well as the moderating role of customer socio-demographic characteristics. Data were collected through a cross-sectional survey of 481 South Korean smartphone consumers. The results indicated that perceived usefulness, perceived ease of use and social influence affected word of mouth. Moreover, hierarchical regression analyses confirmed that the effect of perceived enjoyment on word of mouth was moderated by customer gender, age and education. Finally, the relationship between perceived ease of use and word of mouth was moderated by gender. These results suggest the need to design targeted smartphone marketing strategies that consider users' gender, age and education.