Michael W. McLaughlin in Marketing Profs sets out Rules for Rainmakers (free subscription):
Rainmakers go beyond the superficial to cultivate a holistic and substantive understanding of the customer's strategic and operational issues. Their mindset is that of a business advisor, not simply a vendor. Rainmakers immerse themselves in the high-priority concerns facing all of the customer's executives.
When you are thinking of the B2B customer experience, this is the holy grail all account personnel need to strive for: value added business advisor.
This is not just a matter of training, of course. The people in Staples that are offering you this week's special on highlighters are not just a relationship course away from providing strategic advice, anymore than you or I are just a leadership course away from being CEO of GE.