For an object to be collectible, it has to be unique. A one-off product signed by a celebrity, for instance. But what happens if the product isn’t meant to last? What if it’s meant to be…eaten? Taking advantage of the Super Bowl last month, Subway decided to transform its “Signature” range of sandwiches into unique works of art thanks to the autographs of famous NFL players – signed using a pen with edible ink. The stars created their own custom sandwiches and took part in a signing session with fans. Some fans ate their sandwiches, while sharing the experience on social media, while others kept them – frozen, or embedded in resin – and even resold them. As a result, the operation attracted 43 million impressions and a Subway sandwich sold for 50 dollars on eBay.