Stock up on Firefly kids’ toothbrushes at Walgreens! The toothbrushes are on sale for $1.99. Use a $1.00 Smart Source coupon and pay $0.99 out of pocket. At checkout, receive a $1.00 Register Reward, making the purchase a $0.01 moneymaker! Register Rewards are long, receipt-like coupons that print when a qualifying purchase is made, and can be used on a future transaction.