When a post goes viral, lots of people share your post to people who don't yet like your page. So Facebook made a "Invite" button available so you could invite those people to like your page too, since they liked your post they might like the rest of your page. Well last year people started getting "invite a friend" buttons after inviting say 100 people. Facebook was limiting the invites because of course Zuckerberg wants your every penny: they want you to buy ads and spend money. So they removed the limitation and the "invite friend" button stopped showing. Facebook is really nice and cool and money's not all they want after all, right?! WRONG. The invite button now simply is ignored after a 10 or 20 invites. You can click them all, you're just wasting your time. How do you verify this? Log in from another account and like the post, preferrably from a different connection, a phone perhaps, or a friend's legit FB. Set this up with a friend while you chat on Skype, Whatsapp or something. Go back to your page now. Invite this friend to like your page from the likes list. They won't receive the invite. Tried from several accounts across several locations and got 2 friends from abroad to test with me. Nobody got the invite. Everyone is just working for Facebook for free, they give you no breaks. Everything is paid. Guess most of you knew this, but in case you didn't , clicking that invite button is just placebo.