At participating Starbucks (we would assume nearly all would
participate) if you bring in a reusable tumbler they will provide you
with free coffee (in the tumbler). It doesn't have to be a Starbucks
tumbler, just any tumbler like one you may have gotten from a
promotional event – you know, ones with the words "Smith Bank – We Love
our Customers". Standard size 12 to 16 oz, they most likely will not
fill your jumbo bubba mug. Their purpose? To reduce the environmental
impact of disposable paper cups.