I mean, I know they do that, but my question is some guys there can add over 1000 likes to a website overnight. How do they do that? Is there some software they use?
They probably do have a software but I think something like that might be a little expensive. They are probably outsourcing the fb likes so they wouldn't have to manually do it themselves or rely on purchasing a program. It's probably similar to freelancers outsourcing backlinks but it's just facebook likes. Try going to Freelancer to see if there are gigs that can help you get facebook likes.
Highly doubt it's a software. From my experience it's usually a couple of things, A scammer, with many...many facebook accounts. Or someone who has created and manages numerous facebook pages most likely totalling hundreds of thousands of fans from all over the world and they then share the page they are promoting on all of these groups and then the links build up.
I have a lot of fan pages with more than 500k fans, and when i post a link to another fan page i get lots of like within hours...
Well the thing is they guarantee 1000 or 1500 or whatever "likes". They can't just sit and wait for the likes and time them out. Maybe they can.