The author here - yes, cr4zy, it seems to be isolated to Promoted Posts. I actually put two samples in the writeup. One is a contest and the other is just a status update. Both have the same problem. Furthermore, the contest entrants basically all seemed legit. It was only the Facebook Likes that seemed to be bot-ridden. If this were just freebie-chasing then I would think the non-contest posts would not be having the same issue.

Your second post was promoted to friends of the first post, with their name and photos attached to it, saying that they like your page. So someone from Indonesia who entered the contest ended up being a conduit by which your page was promoted to lots of other Indonesians.

Unfortunately, I don't think there's a way that you can avoid promoting to them in the future. That's really annoying because you will spending a lot of your promotion $ on useless fans. You can still run regular targeted ads, though, that show up on the right side. EDIT: it can be done: http://news.ycombinator.com/item?id=4650476

Click fraud doesn't make sense to me because there's no incentive for it. Promoted posts are priced by reach, so a click, like, comment, share, etc. don't cost anyone anymore. It simply provides free viral distribution via the ticker and newsfeed.

I disagree that the likes are "bot-ridden." I checked out 15 at random. 13 looked real, with lots of recent photos, friends, posts, and gaming app activity. One looked like it was just posting photos from movies (but with a fair number of friends ... a business profile?). The last one was freshly created (seems weird), but most of the posts and comments were posted via the mobile app (seems legit).

I was surprised that none of the 15 were locked down. Fake accounts I see in the US have the most conservative privacy settings.