A simple cardboard slide is an unexpected hit among Millennial parents. When the Pop2Play slide premiered on Amazon this past spring, it sold out within 24 hours, then sold out an additional three times in months that followed. The product, made by toyco WeeWee, is a low-tech pop-up slide made of cardboard. When it’s not being used, it folds flat and can be hidden away—which is likely part of the key to the product’s success. Pop2Play toys “could disrupt a significant industry category” thanks to Millennial parents’ desire to keep large plastic play structures out of their spaces, and their growing aversion to plastic toys in general. In the wake of their immediate popularity, the brand has struck a licensing deal with Mattel, and a foldable cardboard Barbie dreamhouse will be released next month, followed by a Barbie branded slide. (Forbes)