I just ordered a Roku box to handle the Amazon streaming (along with the Netflix and Hulu+ of which I am already a member).
I use the automatic reorder for everything where it is offered. But I set my reorder time to 6 months. Then I just manually reorder when I need more, or cancel after I've had enough. That way it keeps surprise shipments from happening, but I still get the nice discount.
Pioneer VSX-1018AH-K, PDP-5020FD, DV-79AVi
Axiom M22s, VP150, QS8s
Sony PS3, surround backs