Purpose – This paper aims to investigate advertising effectiveness in various social media platforms. The present study uses a proposed framework to explore online advertising in Egypt. From a theoretical point of view, this study examines the relationship among three groups of factors including ad characteristics (perceived ad informativeness/ perceived ad entertainment, vividness, interactivity), online customer engagement and social media ad effectiveness among Egyptian consumers. Design/methodology – The study examines advertising effectiveness in social media in terms of ad attitude and loyalty intentions. An online survey was conducted with 1300 social media users. Findings – The results indicate that there’s a significant positive impact of perceived ad informativeness on ad effectiveness whilst perceived ad entertainment, vividness and interactivity impact on ad effectiveness is insignificant. furthermore, it is observed that perceived ad informativeness and perceived ad entertainment have a positive significant impact on online customer engagement as perceived by Egyptians. Moreover, online customer engagement is found to have a significant positive effect on ad effectiveness. furthermore, online customer engagement is found to mediate the relationship between ad characteristics and social media ad effectiveness.