There is a potential side-effect of the new facebook "like" button, which has currently not reached public awareness, but it probably should.

It starts when you leave the facebook website. I usually don’t log out, my friends don’t log out, and in fact most people don’t log out. We all know this is too much of a hassle.

Now, if I visit a website which has integrated the “like” iframe, facebook might just know that I am there. Because I didn’t log out before. And why shouldn’t facebook track the referrer combined with the user id of every requested iframe?

The problem is, we might see millions of websites using this like button soon. Facebook could basically track all your surfing.

While we’re supposed to “like” the crap out of the world wide web, the referrers are going to feed the “open” graph with far more data than only our clicks:  view volume is much higher than click volume. Knowing which websites we surfed on will prove far more valuable to build up the open graph.

Imagine the value of all that precious data for facebook. Ads with retargeting? No problem anymore. In fact, the whole open graph idea might be the very foundation of a new ad system which could be considered as AdSense on steroids. (Even though I believe that it will never reach the quality of “permission marketing” à la AdWords). And it’s just a question of time, when facebook’s going to release website analytics for the publishers (so long quantcast!!).

Unfortunatly, this idea is quite scary. Facebook is moving at a pace that political and social boundaries simply don’t. Let’s see how much further they can go.

The social fatigue might be close, brother.

(They already know, but you can still click the button for the fun of it!)