Business relationships are just like any other sort of relationships. I have heard it said many times that that people do not mix business with  pleasure or say may I introduce a colleague. We may think that we have to work less hard on our realtionships with colleagues because we are being paid to do a job. Nothing could be further from the truth. If one wants to be successful at work then they are going to have to develop relationships. What kind of relationship you choose to develop will give a fair idea of how you feel about your work. From a purely mathematical point of view. A person will probably spend more of their time with their colleagues than anybody else. What kind of relationship would you like? Would you mix business with pleasure?