In designing our system, we seek to balance two conflicting goals. An ideal system would (1) cause no interference to demand transfers and (2) consume 100% of available spare bandwidth. In order to provide a simple and safe abstraction to applications, we emphasize the former goal and will be satisfied if our protocol makes use of a significant fraction of spare bandwidth. Although it is easy for an adversary to construct scenarios where Nice does not get any throughput in spite of there being sufficient spare capacity in the network, our experiments confirm that in practice, Nice obtains a significant fraction of the throughput of Reno or Vegas when there is spare capacity in the network.