Free Root Beer Floats at Sonic Tonight

From Sonic Drive-In's newsletter:
"Seven really is a lucky number.

That's because June 7 is FREE Root Beer Float Night at SONIC®. Just show up between 8 p.m. and midnight, push the red button and order a free 10-oz. Root Beer Float. There's no catch. It's that easy. So, tell your friends and family and don't miss this sweet deal. Tell you what, text 'freefloat' to 74574, and we'll send you a reminder.

While supplies last, at participating SONIC® Drive-Ins."