Marlowe and "the King" are complete opposites, why do you think they become friends?

Although it is evident from the start that Marlowe is almost the complete opposite of the King – who is always looking to make a deal or find a new way to turn a profit – the two men begin to form a friendship based partially on the fact that they are so different from one and other. Over the course of the novel, we see that their strange friendship, and the different way each man views it, is an intergral part of the plot.