Happy Friday the 13th! Today, Firehouse Subs is offering a FREE Medium Sub with any purchase to people whose first name is Jason, Crystal, or Pamela. If that's you then simply show your photo ID at any U.S. Firehouse Subs today, 5/13, and get a free medium sub with any purchase. Enjoy! The names change every day so check back if your name starts with something other than DA.