Why should recruiters focus on reciprocity?

I have been an advocate for Dr Robert Cialdini’s for nearly 20 years, and his first book Influence The Psychology of Persuasion. Reciprocity is Cialdini’s first of Cialdini’s 7 Principles of Persuasion. Reciprocity is defined by Cialdini as, people being obliged to give back to others in the form of a behaviour, gift, or service…