According to a new book, Facebook's founder, Mark Zuckerberg, discovered that his site could gauge the strength of a relationship, and used to amuse himself by forecasting romantic doom. In his insider expose, The Facebook Effect, which hits shelves June 15 and is being touted as "the Facebook story that can be found nowhere else," technology reporter David Kirkpatrick claims Zuckerberg knows a lot more about his audience than they might realize — including who they're about to break up with, and who they might date next.

How is that possible?
As his engineers added more tracking functionality, the book claims, Zuckerberg would analyze who was looking at whose profiles and for how long, and track changes in wall-writing patterns and photo-tagging efforts — thus deducing who was about to be dumped and predicting new relationships

How accurate were Zuckerberg's predictions?
Kirkpatrick claims Zuckerberg honed the skill to predict breakups with 33% accuracy, calling the odds correctly with about 1 out of 3 couples.

Does Facebook do this now?
Not yet, anyway, says Nick O'Neill at the blog All Facebook, although the company does monitor your behavior "to determine what should be displayed in the feed." Facebook could probably implement a "relationship strength tool" without much difficulty, he says, but users are probably safe from such an "extremely creepy" development..."for now."

How is the commentariat reacting?
With a mix of shivers and sighs. The technical minds at Facebook not only "know far more about you than you likely realize," says Tracy Clark-Flory at, but they "might even be able to recognize things about yourself that even you have yet to realize." On the other hand, says Jen Doll at The Village Voice, it really "doesn't take a Harvard grad" to figure out whose relationships are on the rocks — just some (increasingly old-fashioned) Facebook stalking skills.