@lefteh, RandomMrdan, aisyna, and augustian
What I mean is that write-in votes are only counted for candidates who have registered themselves as a write-in candidate. (This may be different in some places, but I had the impression that it was the same everywhere.)
When Ron Paul announced that he was no longer running for president, he said that while he could not endorse any other candidate, that his followers should NOT vote for him, because he would not be registering as a write-in candidate.