11. The computer readable storage device of claim 10 , wherein stationary scores and the transition scores computed using one of a popularity score and a purchase efficiency score.
11. The computer readable storage device of claim 10 , wherein stationary scores and the transition scores computed using one of a popularity score and a purchase efficiency score. 12. The computer readable storage device of claim 11 , wherein the purchase efficiency score is a linear combination of a count of different purchase related events.