Most of those are very good at syndicating content. Because Facebook doesn't do much in terms of copyright infringement, people can take great content from other places and use it for their own pages. If you do that and include a paid strategy behind it, you have the ability to grow your page quickly.

Distribution & Syndication is the name of the game...Most aren't aware that when your content is shared & liked by those not following your page, you are then given the opportunity to manually invite them to your page.
If you can find a collection of niche groups within facebook & share the content that speaks directly to them- you can jumpstart the engagement that could lead to lots more engagement.

Of course there is a lot more ways to distribute-- but i've found this one the most effective.

If you have any questions or want to screenshare as i walk you through this-- lemme know! :D

There is no specific way to accumulate millions of followers on Facebook but instead overtime and through testing content strategies it's possible to get there.

You are right in assuming that a lot of this is not organic. Facebook as a platform is becoming more PAY-TO-PLAY, so creating a huge following without paid initiatives is very difficult.

It starts with content when looking for strategies to reach these levels. By identifying low effort, high reward content types and testing their validity through short term paid promotions, you can get immediate feedback from your target audience around if they found value from it. From there you should begin to double down on what's working and find ways to enable this content machine to keep running.

I wouldn't overlook the monetization of this audience though. Building an audience for maybe "1 day" monetizing it is foolish.

If you want discuss in more detail specific strategies for building a following for your idea, feel free to schedule a call.

I recommend engagement with your target market via Facebook groups. Post related content that enhances the group and doesn't sound like a sales pitch. Do this in multiple groups and the likes will come.

In short--make great, relevant content and promote it to your target audience... easy right? Well, it depends on the content (obviously).
Honest question: why do you want millions of followers on facebook? It seems like an arbitrary goal--not a bad goal, but I need to understand what value it has to your business needs.

There are different ways of getting likes to your page.
FACEBOOK PAID CAMPAIGNS:
Facebook has different type of paid ad campaigns. In order to get more likes you should combine these two:
- Traffic Campaign: the objective of this campaign is to send more traffic to your website. The ad contains the "like" icon and therefore your likes are going to automatically increase while users visit your website.
- Brand Awareness Campaign: The ad also contains the "like" icon and it's used specifically to get more like volume. (if user clicks on the ad, it is not re-directed to the website).
- Boost Posts: Boosting posts that had previously acquired good engagement on organic. If you know that organically have been doing good, then go ahead an boost them (paid).
FACEBOOK ICONS AND LINKS
Make sure that your website and blog has the Facebook icon. And in your emails and newsletters!
CAMPAIGN INIATIVES
New campaigns iniatives (to push on every channel): for example a give away or contest. Users are able to enter on a give away or contest if they provide their email and like your page (be careful and don't go crazy asking the user to do too many things as it has been proved that more than 2-3 things is way too much). There are some easy to use platform that help you creating these contests.

Hope this helps!