The value proposition with regard to 'Relationship Engagement' in Social Media , in my opinion, is an offer of leadership one-on-one. Social Engagement derives from the use of 'Social Relationship Marketing' through acts of leadership for the sole purpose of serving the greater good. Leadership itself is free - it is a social relationship. When, and if, individuals choose to act on a value proposition delivered in a leader's message it may become a commercial 'engagement' at the choice of the individual. That's my take on the difference between Commercial Engagement Marketing and Social Relationship Marketing. There is no commercial intent in Social Relationship Marketing. It is an act of 'giving'.