Attention, fans of Shake Shack — which is basically everyone, right? — we’ve got some epic news for you. Next week, the New York-based burger chain is opening its 100th location. This milestone comes just 12 years after the first Shack was opened in Madison Square Park. To celebrate this joyous debut, which will be at Boston Seaport, Shake Shack is giving out very special thank you gifts to customers at every single one of its locations. The gift? Free burgers! This is not a drill, people.There are a few rules, though. According to a press release from the company , beginning at 10:30 a.m. August 16, the first 100 customers to each location worldwide will be given a free single ShackBurger. The giveaway extravaganza will end at 12 p.m. or after the first 100 guests, which will probably happen first. This means you better get in line early. That is, if you aren't above eating a burger at 10:30 a.m. We certainly aren't. ( Eater