I am interested in finding out how Healthcare Group Purchasing
Organizations use information technology with their purchasing members
(customers) and what the business focus is of that technology.
 For instance:  MedAssets incorporates a proprietary application
(CrossWalk) that integrates member patient charges and revenue with
their contracted vendors.  This answer would be supported by press
release information, external reviews, company data, etc.

I am interested in learning about the systems for MedAssets, Premier,
Broadlane, Amerinet, and Novation (at least three of these companies).