I think it's suppose to be like sex when a vampire sucks your blood. Or the whole dominance over another person thing. I don't know. It could be symbolic with all sorts of things.
Haha.... I luv vamp flicks...... I think it's more about the fascination of another creature more than anything else..... I mean most people would want to be stronger, faster and look gorgeous.......
But my favorite vampire is Angel. That guy's so unpredictable. He'll talk to you and then suddenly snap your neck. Haha.
And as for moonlight, that series blows.