Organizational scientists have been investigating the role of human relationships vis-a-vis firm productivity for some years. Recently, Social Capital has been theorized to play a central part in the reduction of Organizational transaction costs. We briefly position Social Capital among several theories claiming a role for interpersonal capital, review its theoretical nuances, and test this theoretical structure using a sample of 469 sales professionals from a leading medical services firm. Our findings indicate that trust, communication, and employee focus have significant direct and moderate indirect affects on organizational commitment.