This research study was carried out to empirically examine the relationship between social media marketing and business success of automobile car dealers in Rivers State, Nigeria. The study involved one hundred and sixty (160) respondents using questionnaire as the major instrument. After data cleaning one hundred and forty-three (143) copies of questionnaire were used for analysis with statistical tool Spearman Rank Order correlation coefficient with statistical package for social science (SPSS). It was found that there is a significant relationship between Facebook, Twitter and YouTube that significantly influenced sales growth, market share and profitability. The study concluded that Facebook, Twitter and YouTube significantly influence sales growth, market share and profitability of automobile car dealers in Rivers State. The study recommends amongst others that: Firms should make Facebook, Twitter and YouTube advertisement more catchy, appealing and trendy in order for online customers to patronize their products. The study suggested that more empirical research should be carried out on other social media platforms such as MySpace, LinkedIn, Friendster, Kyte and Istagram. This study further suggests that additional studies should be carried out in other states of the country so that we can compare the outcome with the present study.