Click farms like every page they can, far more than just the pages they were paid to like; the theory is that they will evade detection this way. Paying for "legitimate" facebook exposure will expose you to the click farms as well, and that will be the absolute majority of your gained likes. In this way facebook ads give a huge, but useless, gain in "Likes".
Since click farms are far far more engaged than the average fb user, this means that invariably, your ad will be steered actively by fb towards click farms!
So if you pay for fb ads you are in effect wasting your money because fb is forcing your ad to be shown to those who shouldn't see your ads.
And if you don't pay either for legitimate or fraudulent likes, you will still get a large fake following because they are using you to disguise their activity.
Does that matter? I mean, obviously if you're trying to work out whether it's worth paying for Facebook ads, it's worth being aware that a large number of Likes isn't necessarily a sign of a successful ad, but you don't know the "value" of a Like in advance anyway. If you discover that every 1,000 Likes you get 10 more sales (or whatever), then you can work out whether it's worth spending money for an ad that will likely bring in 1,000 Likes, whether 990 of those likes are "genuine" Likes that don't turn into sales, or 990 of the Likes are click farm Likes.
I mean, I've never advertised on Facebook, I don't know anything about it, but I would have thought you need to measure the actual effectiveness of your ads; whether click farm fake Likes are contributing to this overall effectiveness or not doesn't seem relevant to the end result.
And frankly, the whole thing is fucking ridiculous to even have to explain. FB does all sorts of shady/hacky shit to make money in a way that is totally incongruous with the needs and desires of both content consumers and content creators. Someone will come along with a simpler model that makes sense, and everyone will move away from facebook like they did from digg->reddit.
the video mentioned how real/useful engagement didn't change before and after he got all those fake likes
According to the video, the click farmers will like the page itself, but not any content it posts.
If your page likes are mostly fake, your posts likes will be proportionately lower.
The auther discovered that Facebook tests your posts among your following, and uses the % that liked the post as a signal as to whether it should show it to the rest of your network.
Now, if you are paying farmers for likes, they might also be liking the content you post. If you're not paying for likes at all, but you have a bunch of fake likes on your page, your posts will get proportionately fewer likes, and FB will show your post to fewer people.
The point was ultimately:
By buying likes, legitimately or not, your page will attract likes from fake accounts -- Which due to the aforementioned reasons will tank the presence of your page in the news feed of real users.
The only workaround from this position is to promote your posts either through legitimate or illegitimate means.
The other byproduct of this notion is that using the free coupons that Facebook tends to offer can cause more damage than they are supposedly supposed to fix.
It's also a much cheaper method than paying FB to promote to your click farm fans.