Wouldn't it be great if you could instantly share an aspect of your application with everyone who plays a part in getting the job done? Without having to start an untold number of email threads that then get forwarded to other people, until it's impossible to know who's in charge of what?
When you share a business object with the social network—like a Sales Opportunity or a Purchase Order—you create a Social Object. With the Social Object, you can bring all your stakeholders together in a single place to get the collaborative ball rolling—and keep a record of everything that's transpired so new folks can easily jump in and come up to speed.