Both parties may be more willing to confidentially tell a disinterested third party more than they would tell each other. This additional information can be used to generate more efficient agreements. If negotiations fail Add complicated exchanges like contingency clauses. Find your reservation point. That is, where are you indifferent to negotiating an agreement or not.
Most people have a target.
Fewer, know their bottom line. Not knowing your reservation point can result in unprepared intuitive decisions cutting off negotiations. Distributive approach - how best to cut the pie, claiming. How to gain advantage - Gain knowledge. Try to deduce the other party's reservation point, that point where they are indifferent to signing an agreement or not.