Nonrivalry has the implication that the efficient price is zero, since the marginalcost of another viewer is zero.
非竞争性意味着有效价格为零，因为增加一个观众的边际成本为零。
2
At any price above marginalcost, the airline is better off selling a ticket than flying with the seat empty.
只要在边际成本以上的任意价位出售机票，是比空航划算的。
3
However, there are many firms that have market power or monopoly power, which means that they can increase their price above marginalcost and sustain sales for a long period of time. [1].