At Caribou Coffee, you can fill your reusable mug with a free Caribou’s Coffee of the Day in honor of Earth Day. Don’t forget you save 50¢ on all other drinks at Caribou when you use a reusable mug.
Over at Starbucks, your reusable mug will get you your choice of a free Starbucks coffee or tea. Starbucks offers a 10¢ discount each time you use a reusable mug.
Make sure to check that your local Caribou Coffee and Starbucks are participating before you go.