The inherent problem with professional sales is the knowledge gap.  Years ago, I heard someone say expertise requires the accumulation of 50,000 units of knowledge.  The problem occurs when people reach 10,000 units of knowledge and believe they know the subject at a high level while being utterly unaware of the remaining 40,000 units of knowledge.   The 40,000-unit deficit is routine in the field of professional sales.  This reality is the sales skills gap (SSG), a significant challenge facing most sales teams today.