Fritz,
The Like button will only show the faces of the friends of the user that is logged into Facebook. The idea is to help a user gauge who else, of their friends, likes the current page. It is not meant to promote everyone who likes the page. This is done by Facebook to help add a social context to Like'ing something so that a user really knows if the Like's are more relevant to them.
So, if there are 10 Likes on a page, but you are only seeing your face, that means that 9 other people who are not friends with you on Facebook Like that page as well.
Hope that helps explain!
Alex