The paper "ISP and Egress Path Selection for Multihomed Networks" written by Dhamdhere and Dovrolis and presented at IEEE INFOCOM'06 discusses a solution to select the best ISPs for multihommed stub depending on traffic patterns of the stub.

The idea is simple, first, determine the traffic top X prefixes of the stub. Determine the possible ISPs for the stub and use stochastic techniques to detemine the subset of ISP to subscribe to and how to perform the best egress path selection.