Brad Spangler explains the Best Alternative to a Negotiated Agreement (BATNA), a key concept for negotiators of all sorts.
Having a good BATNA increases your negotiating power. Therefore, it is important to improve your BATNA whenever possible. Good negotiators know when their opponent is desperate for an agreement. When that occurs, they will demand much more, knowing their opponent will have to give in. If the opponent apparently has many options outside of negotiation, however, they are likely to get many more concessions, in an effort to keep them at the negotiating table. Thus making your BATNA as strong as possible before negotiating, and then making that BATNA known to your opponent will strengthen your negotiating position.
(HT: Penelope Trunk.)