Register Rewards will generally print out for 1 cent higher than the ad says. Product x would print a reward for $5 not the $4.99 stated in the ad. These rewards count as a manufacture coupons and only 1 manufacture coupon can be used per product. If you try to use your $5 register reward to pay for product y which you also have a $1 off coupon for from the Sunday paper, you will be over the allowed 1 coupon per item. The complete this transaction you will need to purchase a filler item like a small piece of candy or a pencil for the transaction to accept 2 coupons. (Walgreens coupons in the ad do not count as a manufacture coupon, so you can use it with 1 manufacture coupon.) I always use my dollar off manufacture coupons first than give my rewards in case something doesn't work. This way I will have a reward left and not a dollar off manufacture coupon.
You can purchase multiple items as long as they are in separate transactions! Walgreens does not have cards so there is no way to track a transaction to you or your household. This is how you can get some great deals and stock up! You can purchase 3 of product x in 3 different transactions and get 3 $5 register rewards for future use. The next week you can put the $5 rewards toward 3 of product y. Each of these rewards must be used in separate transactions, so if you have 3 rewards from product x, than you must use them in 3 transactions for product y. If you have a reward for product x and one for product y than you can put 2 together and purchase product z and product a in one transaction.
I know this is confusing so if you have any questions feel free to contact me! Good luck and please share your great deals with me!