Starbucks can initially start promoting their idea on reusable mugs. For which, Starbucks may consider distributing mugs for free or may be as less as 1$ Each mug has a barcode on it. Each person buying this mug gets a punch hole card, if a person gets their own cup for 10 days, Starbucks would photo print their picture on the mug and can also give them gift vouchers. May be Starbucks can consider tieing up with Kodak to earn the cost advantage on photo printing. Mugs can be sold as per the sizes offered by StarBucks.