[achompas]

Right, the article examines breakups ex-post. That is, they can only identify breakups after they happen.

Ex-ante, though...I remember hearing somewhere that Zuckerberg used to predict when people were about to split, because they could see whose profiles you were looking at.

If you started checking out potential partners with a high frequency, and you were in a relationship, Zuck et al. knew it wouldn't last long.