That's not how it works. Instead, Crelm toothpaste will note that you've liked them and forevermore your friends will get stories posted directly by Crelm toothpaste with the heading
Jerf likes Crelm Toothpaste
[blah blah blah a big picture depicting how wonderful Crelm toothpaste is]
So when you say "followed by your own message", the "your" is the advertiser? (That's valid, just clarifying.)
Of course, it could be no other way, since I'm hardly the only one who feels this way.
As my message implies, I'm not actually on Facebook, but my wife yesterday registered a complaint about a cousin I have that "likes" a couple dozen things a day. (And again, disclaimer, I don't actually take the HN discussions to her, as a non-tech person she ends up bringing them to me. These are not uncommon feelings.) Of course Facebook is just selling eyeballs, but there's a delicate dance of deception they must do with their users to not let it become blatent. If it becomes blindingly obvious that the users are taking second priority to the real customers, the users will eventually leave, and then where will the real customers be?
Jerf likes Crelm Toothpaste [blah blah blah a big picture depicting how wonderful Crelm toothpaste is]