Under the terms of the offer, if you buy any sub (6-inch or Footlong) plus a 30-oz drink, you get another one of equal or less value for free to give to anyone you like (including yourself).
The sandwich chain has occasionally sent out coupons for "buy a 6-inch sub and 30-oz drink and get a free 6-inch sub" in my area but the including the Footlong as well is rare. On a side note, I've always thought the inclusion of the 30-oz drink kind of flew in the face of their market positioning as a "healthy" fast food choice (although, it's true you could always fill up the cup with unsweetened tea).
Image via Subway.
