Is Facebook a Potemkin village?

When I surf the web, I see a lot of "sign up for facebook" ads, as if they are seeking new members.

But what has annoyed me in the past weeks is that when I use Chrome, all of a sudden, a tab with Facebook opens when I didn't request it to be opened.

This  is now happening when I used a different browser that I don't use for my mail and haven't used to open Facebook...

This seems to be an old problem: This discussion claims it is because you have the facebook messanger for Windows and that they solved the problem in 2014...

Uh, no, I don't use Facebook messenger.

Mozilla support says run TDDS KILLER to stop this.

I'll put a followup post if this works.

But I wonder:

Question: Is facebook paid for the number of times people open their page?