Celebrate summer with a half-price shake at Sonic!   This offer is valid this coming Thursday (6/20) at participating locations. You don't need to print a coupon - enjoy! Thanks, Freebies 4 Mom! Sonic Half-Price Shakes (6/20) was first posted on June 18, 2013 at 12:00 pm. ©2008-12 Deal Seeking Mom™. All rights reserved. Use of [...]