David Pogue: I don’t use Snapchat. And no wonder: Most people who use it are under 25, and 70 percent of them are female. I’m neither. At the same time, I’ve been dying to understand Snapchat. I mean, it’s a major cultural force: 200 million people are using it. They send 20,000 photos a second … Continue reading Now I Get It: Snapchat