With more than 1,200 locations across the U.S., Firehouse Subs has built a reputation around limited-time giveaways. But the sandwich chain’s latest promotion is turning heads for one very specific reason: customers named Mike—or anything close to it—can score a free sub just by showing ID. According to The New York Post , on May 6, the company launched a one-day promotion tied to its new Steak & Cheese Melt sandwich, offering a free medium sub to anyone whose name falls within the brand’s “Mike family.” That includes Michael, Mike, Mikey, Miguel, Michelle, Michele, Michaela, and similar variations. Customers only need to present a valid photo ID at participating U.S. locations to redeem the offer, though the company noted that availability may vary by individual franchise operator. The rollout immediately sparked online chatter because of one obvious detail: the campaign arrives at a moment when rival chain Jersey Mike's Subs is expanding aggressively and reportedly preparing for a public offering.…