1. A method for managing a plurality of instances of a Wide Area Network (WAN) optimizer executing on an intermediary device, the method comprising: (a) establishing, on a device intermediary to a plurality of clients and a plurality of servers, a plurality of instances of a Wide Area Network (WAN) optimizer to accelerate WAN communications between the plurality of clients and the plurality of servers; (b) monitoring, by the device, network traffic traversing the device for each of the plurality of instances of the WAN optimizer; and (c) selecting, by a manager executing on the device responsive to the monitoring, a change of a load balancing scheme to load balance the plurality of instances of the WAN optimizer.