Sure thing! This would be a great way to build your coffee shop's brand. For example, you can sell a 12-ounce reusable coffee cup and customers that bring this cup with them when they purchase coffee from your business can receive 10% off the original 12-ounce coffee price as a token of appreciation for being a "green" customer.  You can go the extra mile and turn this into a loyalty program. For customers who purchase the reusable cup, give them a punch card. For every 10 times that they bring their reusable cup back to your business to use for coffee, they will receive a coupon for 15% off their next transaction or a free cup of coffee. The loyalty reward is totally up to you!