<p>I upvote immediately when I'm very curious about the answer.  Why not?  I've already benefited from the question since it piqued my interest, and I'd like to increase its visibility so that someone else can answer.</p>

<p>I also upvote questions when I think it's a good question and I am about to provide an answer.  This is because I am about to benefit from the question by its having given me the opportunity to answer it.</p>
