Annalee Newitz offers a theory of virality:

To share a story is in part to take ownership of it, especially because you are often able to comment on a story that you are sharing on social media. If you can share a piece of information that’s an absolute truth – whether that’s how to uninstall apps on your phone, or what the NSA is really doing – you too become a truth teller. And that feels good. Just as good as it does to be the person who has the cutest cat picture on the Internet.

So that leaves us with the stories that don’t make it. These are the articles and essays that have fallen into the valley of ambiguity – reports on important scientific findings with difficult-to-interpret results, political news with a long and tangled back story attached, and opinion essays that require us to account for points of view that may be unfamiliar or strange.

We just want to share stories that make us seem like we know something. Most of all, we don’t want to say something that we didn’t intend.