answer:Theoretically, anyone on your friends list “subscribes” to your wall posts, unless they’ve blocked updates from you. Whether they’ll see it could depend on a few factors: how often you post, how often they check their news feed, how many other friends they have, and probably others that I don’t know about. If you have a message for a specific friend, post on their wall. If you want to share a link or a photo with everyone on your friends list, post it on your wall. If you have some text that you want to share with everyone, and it’s short, put it in a status update. If it’s long, put it in a note. You can tag people on your friends list in a note, so if there’s someone in particular (or a group of someones) that you want to see it, tag ‘em and they’ll see it for sure. I don’t think there’s a way to tell whether someone has blocked your updates in their news feed.