How they gain insane followers number on fb pages?

Hi everyone,
I'm new here and i wonder and asked many times how some pages in fb get my like and my follow without my knowledge. They made a huge numbers of followers in no time, can anyone explain this?
Thanks,

 

They either purchase likes and followers or the content is viral worthy.

 

Or are you asking about Facebook Like Jacking/Clickjacking?

 

These are the basic tips for you to get likes on your Facebook page

- update your page regularly
- post interesting status wall
- invite more friends to like your page
- promote your page to other social networking sites
- advertise it to google adwords or Social ad (with pay)
- buy Facebook likes from freelancers on webs like SEOclerks