Like a monthly wine club -- the ability in the recurring order subscription feature to assign specific products to each month's recurring orders - pre-defined when you are building the subscription product, and have them automatically populate the recurring orders, or at any point before the recurring orders are "placed" automatically. The product (or set of products or kit of products) would be based on a pre-assigned set of "kits" for a particular subscription (third month of the annual subscription, subscribers get X, Y, and Z), or based on which month the order is going out (In March subscribers get A, B and C)