The horror film “Smile” was a huge hit, earning $22 million in just three days on a $17 million budget. It uses a “chain of curses” idea similar to “The Ring,” but with a modern twist. One standout feature was its creative marketing, in which actors with unsettling smiles appeared at live baseball games, quickly going viral on social media. The film does a great job of turning the everyday “smile” into something truly frightening.