Facebook's dirty data

Interesting argument that Facebook's graph search is going to be inherently flawed, because Facebook's data is dirty:

It turns out as much as half of the links between objects and interests contained in FB are dirty—i.e. there is no true affinity between the like and the object or it’s stale. Never mind does the data not really represent user intent... but the user did not even ‘like’ what she was liking.

How is this possible? Let me explain.

In the brand advertiser world CPMs have been the preferred measurement (people aren’t going to click an ad for Coke; instead its purpose is to influence you). For the past several years big advertisers on FB have actually been directing massive amounts of paid media to acquire fans. They quite literally bought likes.