You have to mention the offer when ordering to take advantage of it though.
Seems like a pretty good opportunity as any to try out the new Chocolate Mint Holiday Shake. It's a little bit cold to be eating/drinking ice cream for me, but I know some people who love ice cream during the winter.
Sonic's shakes are available in Chocolate Mint (limited-time only), Vanilla, Chocolate, Strawberry, Pineapple, Banana, and Caramel.
The offer is good at participating locations only.
Photo via Sonic.
