Perhaps of interest: BBC technology correspondent Rory Cellan-Jones' investgiation into fake likes from earlier this year:

http://www.bbc.com/news/technology-18813237

Also recall the company that estimated that 80% of its clicks are coming from bots (based on disabled Javascript).

http://techcrunch.com/2012/07/30/startup-claims-80-of-its-fa...

http://news.ycombinator.com/item?id=4312731

(The original link from the HN submission is unfortunately gone)

I found roughly the same thing comparing apache logs with google analytics.

A direct conspiracy would be a pretty bad business model, but fake friend and spam disseminating accounts may be less likely to be canceled if bots or minions keep them active with bogus activity.

If ~80% of profits is really from bots, then it's hard for fb not to turn a blind eye to these accounts.