Entrepreneurs are increasingly using social media in running their businesses. This phenomenon is remarkable especially in developing countries where entrepreneurs now exploit business opportunities by using cheaper platforms. Prior studies claim that social media plays a crucial role in establishing a business and ensuring its survival through effective marketing. However, from the context of developing countries, limited research has sought to understand the role of social media in motivating entrepreneurs to start and market their businesses. This current study seeks to investigate this issue through a field study comprising interviews with Nigerian entrepreneurs. The research explores how social media shapes Nigerian entrepreneurs’ motivation to start a business and how they market their businesses via social media. It was found that most of the entrepreneurs interviewed were opportunity-driven rather than necessitydriven due to opportunities afforded by SM. Furthermore, entrepreneurs devised several social media marketing approaches across different platforms to reach their audiences.