Ask your host. For me, I am not voting for either. I must be influential. Since the prevailing logic is that my failure to vote for Romney is a vote for Obama, that means that my failure to vote for Obama is a vote for Romney. Add those two votes to my write in and I get three votes.
I think the underlying assumption here is were you to vote that you'd be inclined to vote for the republican candidate, not the democrat one.
Incorrect or not, it is the underlying assumption.