It's easy to gauge the success of a movie: You look at the box office gross.
But gauging its cultural impact and its popularity among children can be more difficult. Then again, maybe not.
Consider the newest movie in the Marvel Cinematic Universe, Avengers: Endgame (PG-13). And then visit your nearest McDonald’s and order a Happy Meal.
McDonald’s not only emblazoned the toy and box with images from the film -- which is common for tie-ins -- but it also placed the Endgames logo on the yogurt tube, the milk...