Negotiations over the internet

I recently attended a conference where several people (including the fascinating and influential Bob Cialdini) referenced this Stanford GSB study on email negotations. The summary is:

When neither common ingroup status nor a personalized relationship existed between negotiators, negotiations were more likely to end in impasse. These results are attributable to the positive influence of mutual self-disclosure and common group membership on negotiation processes and rapport between negotiators.

In other words, sharing personal information about yourself and being members of a common group creates a higher likelihood of a successful negotiation.