The secrets of Upworthy, revealed in New York Magazine.
ADDED: The linked article is way too long and obfuscatory. Is Upworthy about building traffic for the ultimate purpose of monetizing and cashing in or is it a political propaganda operation at heart?
It's hard for the reader even to notice that should be the central question. If you do, good luck trying to find an answer in that prose that's cluttered with "Star Trek posters, felt Muppet versions of [it doesn't matter], and a cat named Bones with an unerring instinct to hop on the desk during work-related videoconferences, nuzzling his head at [an editor] and, by extension, pointing his anus directly at the camera lens...." and blah blah blah.