muirford's right - some of the messages are exactly that. OTOH, on our fan page, I can - with the simple click of a button - annoy all my FB friends with a request to become a fan, join a group, etc. I try not to do that unless I think it's something of uber-interest to a particular subset of my FB friend. I DEFINITELY don't do that often (like twice ever) with our fan page. I think it would be too annoying to be effective.
The referrals that muirford's referring have actually brought us fans that 1. havn't stayed here; 2., aren't friends or familiy of DH or myself; or 3., aren't friends of other fans. I've looked up the profile pages of some of these folk, and it's the only way I can explain it - they're not in this part of the country, or show publicly any connection to us. Must be something in their browsing that FB took note of.