While your enthusiasm is to be expected and commended, this course of action is not always in your best interest. When it comes to negotiating salary, one has to be particularly sensitive not to alienate the other party. You can do this by determining ahead of time exactly what you want to achieve in the negotiation. It is important that you negotiate in order to achieve your goals rather than squeeze the company for every last dime. One does not want to come across as greedy.
Bears make money.
Pigs get slaughtered. It is surprising how many people enter into a negotiation without a clear sense of what they want to achieve. It's like going on a trip without a map. You're bound to wind up somewhere, but it may not be a place where you wanted to be. Determine answers to these questions in advance.