Marketing has not always existed, it owes its emergence and prosperity to the evolution of the economy and the ever-increasing modification of human behavior. Marketing is an integrative and transversal science, that is to say, a science that uses other sciences (statistics, mathematics, economics, psychology, sociology, etc.) and intervenes in all fields of activity to establish its influence. It would therefore be important for many Cameroonian SMEs to integrate marketing in all its forms in order to optimize their profits and develop their business sector for a better monitoring and development of customers. Finally, marketing is a science of dynamic management that is to say that the man of marketing must adapt to the context and realities of his environment, but, at the same time must change behaviors. This study focuses on how to build customer loyalty in a Small and Medium Enterprise in order to maximize profit. A challenge for Cameroonian SMEs attempts to shed light on this issue.