I never vote for mine in the first place.But I have had votes,I think I have placed in the top three a few times.
I will ALWAYS feel contest should be about the best IMAGE. Voting for yourself or your friends is not going to tell us anything about the best image. I would rather have just one vote from a stranger than 10 from friends "doing me a favor" and 1 from myself. Yes, I would rather have 1 vote than 16!
So I don't give a damn where I place in a contest. To me, I "win" when I get even 1 vote. If it is not my vote and not somebody doing me a favor that means someone voted on my image simply because they liked it, and nothing more. That is how I judge my work and, ultimately, I enter contest to judge the quality of my work. Not for exposure or to see how many votes I can get.