We consider an endogenous leader-follower relationship in a network goods market, such as those found in the information and communication technology industries, where we observe network externalities and product compatibility (hereafter, network compatibility effects). Using the framework of an endogenous timing game, we examine how network compatibility effects affect strategic relationships between firms and the leader-follower relationship. In particular, we demonstrate that if there are sufficient asymmetric network compatibility effects between the firms, there is a unique subgame perfect Nash equilibrium in the endogenous timing game, where the firm providing the product with a large (small) network compatibility effect becomes a leader (follower) in the case of quantity competition. However, in the cases of price competition and quantity competition with consumers' ex ante expectations for network size, the reverse result arises.