In a spoof on March Madness, they've been running a single elimination tournament ("BrackeTOTlogy: The Final Fry") pitting their Tot plushies against each other based on fan voting on their Facebook page.
This Thursday marks the culmination of the tourney spoof with the winner to be declared between Count-Tot-Ula and Kitty Tot.
The offer is good at participating Sonic locations and a small order of Tots is regularly $1 on the Sonic menu.