Ok this is more of a rant, I will be honest. Of the books i have read lately, there have been at least 3; that have referenced the copper smell of blood. One used the reference across the entire book. I can't remember exactly what copper smells like... but blood, blood smells like iron.
Thus blatant incorrect reference in so many books just irked me. If you are talking about vampires or bloody fights know the right blood references, please.