Engagement is a key measure of health for social media platforms. It's measureed not only by how much time users spend there, but also how often they upload, share, comment and "like." Investors want to know that these platforms are integrated into users' lives so that advertising revenue can continue to grow. But some platforms, including Snapchat and Facebook, are seeing engagement decline. Jessi Hempel, a senior writer for Wired magazine, points to a gradual boundary setting with social media that she thinks a lot of people have been doing, intentionally or not. (08/17/18)