Upworthy CEO and co-founder Eli Pariser talks about what makes people want to share content: It's not just the headlines, he says.

Pariser, who honed his data-driven chops at MoveOn.org, said the media's obsession with Upworthy headlines misses half the story. "Some of the stories about us have focused too much on the headlines, but to have content that's really shareable, it has to be something people actually want to share," he said. "We look at how much people click, but also how much people share [after they click]. The only way to get something that does really well is to deliver on the quality that you're promising in the headline."