Every time I buy something at a 7-11,I get a small paper token the size of a postage stamp with my change,sometimes am given half a dozen of these at once. Over a month trip,and about three visits a day,that's a lot of tokens. I leave them in my hotel room,with all the accumulated coinage,for the maid as they might be valuable to somebody? Are they actually worth leaving though,or is it insulting to the cleaner to be given a bundle of these mystery tokens? Of course I leave money too,but what about these strange micro vouchers,anybody know why they exist?