That's because developing countries create "click farms"
They get paid $1 per hr to click like to every page on the list they get from a head manager.
This is the reason why buying likes to your page is getting to be a useless feature. However there are niches that are filled with more spammy activity.
Concentrate on making your posts virality fast as soon as you post. Reason being is their algo is designed that when you post something, your post only goes to about 3% of you list. If they like it and share it, Facebook allows it to go further to more % of your list.
Hope this helped some people understand Facebook more and if you need help feel free to add me on Skype:ericsebastion