It is novel that the theory of Markov chains is used to study scale-free networks. There are some important problems that may be explored by this approach. For example, we may consider calculating the joint degree distribution of a node pair in
scale-free networks by using Markov chains, and calculating the clustering coefficient of scale-free networks. This approach may indicate an important direction for us to investigate the underlying mechanisms of growing networks, since the structural properties of Markov chains have been applied to characterize many natural phenomena.