The present paper is a collection of research studies on the professional activity of the self-employed worker, still misunderstood or even despised in Africa and specifically in Gabon. Through the study of factors such as poor word-of-mouth communication, inadequate psychological profile, and MSDs altering the professional activity of self-employed workers, we assessed the links these factors have with performance, cognitive load management and job satisfaction. Spice sellers, thrift shop vendors and truck drivers took part in our various research projects. The results show that the credibility of the traditional message influences product pricing in the spice saleswoman, that the conscientiousness and neuroticism profiles promote effective management in the thrift shop salesperson, and that MSD management does not influence satisfaction in the truck driver.