The box is used for bait. New parents want the box, it's free and full of great stuff. To get the box, they need to visit a physician. As others pointed out,

The box is used for bait. New parents want the box, it's free and full of great stuff. To get the box, they need to visit a physician. As others pointed out, a single visit to a physician can help to identify issues with not only baby but also mom.