<p>A critical factor influencing consumer purchase decisions is the propagation of information by word of mouth (WOM). One important method for promoting the spread of WOM information involves implementing a reward mechanism to stimulate user participation. This paper describes a WOM spreading model that utilizes a reward mechanism and explores the impact of the reward mechanism on consumer WOM propagation and the consequent effect on product sales. First, the existence of equilibrium points in the model is proven, and the local and global asymptotic stability characteristics of these equilibria are analyzed. Second, two key parameters are selected for the analysis of optimal control, namely the contact rate of individuals with purchase intentions converting into spreaders and the probability of spreaders converting into hesitant individuals. Finally, the results of numerical simulations are presented to verify the accuracy of the theoretical analysis. The results from this study demonstrate that increasing the number of spreaders and reducing the number of hesitant individuals effectively promotes WOM spreading. Furthermore, introducing a reward mechanism during the product sales process motivates consumers to actively engage in product WOM spreading.</p>