Courtship is expensive and complicated by design, and it’s the limiting factor of the sexual fulfillment of men. Women impose costs on men to gain sexual access for very good reasons: to test their genetic fitness and their long-term potential supporting a family. If courtship is costly and the costs are not clearly defined, this not only tests a man’s motivation toward a specific woman, it also acts to monopolize a man’s resources so he can’t afford to woo anyone else. Pornography and prostitution are popular because they arrive at sexual end goals, or a reasonable facsimile, with more clarity and lower costs than in the mating market.