It means you can easily check up on that person without hunting for their posts. You can see where they posted, when they logged on last etc. Why Sarah, is somebody WATCHING you? (Twilight Zone music)
They should rename it to "Favourite Users". Basically it gives you a shortcut to the profiles of your friends (easier to look up when they last logged in) and it can notify when they made a post. Similar to a web browser notifying you when a favourite page has been updated. The most useful feature I find is for sending Private Messages. All users in your watched list are available in the Select User drop-down box when you create a new PM. Just one other way to PM somebody.
Just FYI for anyone who doesn't know, to add a watched user, click on the person's name (beside any post). You'll get to their profile, and be able to add them to your watched user list through a link, "Add to watched user list" along the top. To manage your watched user list, click on "Options" and then "Manage Your Watched Users List."
I personally like the watched users thing. Convient for whenever I write a private message. No need to search for the person. And it also makes me feel like I have friends lol.. lame
*Rockwell plays in the background, Michael Jackson sings*: "I always feel like someone is watching me..." (Bad 80's trivia: the guy who did this song was the son of the head of Motown records and they got "The Gloved One" to sing on the song as a favor)
