At the moment, Facebook assumes that people click on exactly the material that they want to click on, and that if it serves up a lot of clickbaity curiosity-gap headlines, then it’s giving its users what they want. Whereas in reality, those headlines are annoying. Curiosity-gap headlines are a bit like German sentences: you don’t know what they mean until you get to the end, which means that the only way to find out what your friend is saying is to click on the headline and serve up another pageview to Upworthy. (Or ViralNova, or Distractify, or whomever.) It’s basically a way of hacking real-world friendships for profit, and there’s no way Facebook is going to allow it to continue indefinitely.
All of which is to say that the massive advantage which Upworthy has … is certain to go away. It’s a temporary phenomenon, a function of the fact that Upworthy is better than anybody else at turbocharging virality by using artificially-optimized curiosity-gap headlines as a way of sending a (false) message to Facebook that those headlines are the stories its users really want to read. Upworthy’s formula will work until it doesn’t.