I replied above in another person's comment that it is no longer out of the real of possibility that one of FB's business models is to covertly financially support these click/like farms so that they encourage ad buyers like myself to keep spending $5 here and $10 there on advertising with the belief that it's actually working for them.
Pay some group of kids $100 in VN ($100 goes a LONG way there) to create and manage garbage accounts, and then like the smallest and newest of FB pages that pay the $5 or $10 to advertise so as to make it seem as though that person's ad is successful.
On a side note, isn't it strange that these farms seem to come from developing countries/areas?
Why wouldn't FB work harder to delete these fake accounts, especially if 1) they've been called out on it, and 2) FB page owners who have advertised in the past are pissed off about it.
If FB sweep deletes these accounts once a year, as both M and J claim, then why couldn't they increase the frequency?