A filmmaker made a short documentary about this happy-go-lucky teenager on death row, called My Last Days. It showed Zach living happily, hanging out with his family, and playing music. Everybody loved Zach. When you see the footage, you can’t help but like him. As you watch him laugh and love and sing, you catch yourself forgetting: this kid is about to die. Zach’s family tells the camera how knowing he would die has helped them realize what matters in life and to find true meaning. “It’s really simple, actually,” Zach says. “Just try and make people happy.” As the 22-minute film closes, Zach looks into the camera, smiling, and says, “I want to be remembered as the kid who went down fighting, and didn’t really lose.” Not long after he said those words, Zach passed away. When Eli Pariser and Peter Koechley of Upworthy saw the film, they thought, This is a story that needs to be heard. Now just over a year old, Upworthy has become quite popular. In fact, it recently hit 30 million monthly visitors, making it, according to the Business Insider, the fastest-growing media company in history.* (Seven-year-old BuzzFeed was serving 50 million monthly visitors at the time.) The Zach Sobiech story illustrates how Upworthy used rapid feedback to do it: According to Upworthy’s calculations, My Last Days had the potential to reach a lot of people. But so far, few had seen it. The filmmaker had posted the documentary under the headline, “My Last Days: Meet Zach Sobiech.” Though descriptive, it was suboptimal packaging. In the ADD world of Facebook and Twitter, it’s no surprise that few people clicked. Upworthy reposted the video with a new title: “We Lost This Kid 80 Years Too Early. I’m Glad He Went Out with a Bang,” and shared it with a small number of its subscribers, then waited to see who clicked.