Bargain at Sonic Drive-In! 1/2 Price Shakes All Day (12/21)December 18, 2012 By Kelli This post may contain affiliate links or sponsored content, read our Disclosure Policy.On Friday, December 21st, head to Sonic Drive-In restaurants to score 1/2 price shakes all day! Go here for more details and to find a drive-in nearest to you.Thanks, The Coupon Centsation!Stay updated on the latest freebies and bargains, “Like” Freebie Finding Mom on Facebook! Oh, and do you wanna learn more about Freebies? If so, check out my “What is a Freebie?” blog!