said 10 months, 3 weeks ago:
@deereinhardt, I guess Facebook assumes that if you only have a limited number of fans, your page is quite new and so your number of fans has just grown recently.
A fan who just recently liked a page is still more engaged than someone, who has subscribed a year ago and not interacted with the page recently – thus will not see the page’s udpates.
Promoting a post should help to reactivate that old fans, who haven’t seen your posts in a while.
I hope my thinking makes sense…