In the world of negotiations, one of the most important things that we  can do is to be clear. 

We want the other side to understand what we are  asking them for. We also want to make sure where we stand on the issues.  However, there will be times that despite the negotiation styles and  negotiating techniques that we are using, we run into issues in a  negotiation that we might not want to advertise to either the other side or to the world.  

In cases like this, back-channel negotiations can provide temporary  protection from deal spoilers and too much public scrutiny.