In this paper, we study the multicast routing problem in broadband networks. The multicast routing problem, also known as the Steiner tree problem, has been well studied in the literature. However, less attention has been made for the definition of link costs and evaluating the performance of multicast routing algorithm from the network revenue point of view. Therefore, in this paper, we examined three approaches for defining link costs, namely, the Markov Decision Process-based (MDP), the Competitive On-Line (COL) routing-based and the linear-based approaches. Two heuristic multicast algorithms, TMR and MSPF. were developed for investigating the performance of these approaches. We proposed a new performance metric, referred to as the fractional reward loss, to evaluate the multicast routing algorithm. Performance of the multicast algorithms under different link cost functions was evaluated via simulations on a 20-node random graph. Our simulation results indicated that the way of defining link costs affects the performance of the multicast routing algorithms significantly and the best performance is yielded when using the MDP-based link costs.