The sexual market place (or SMP) is the collection of men and women who have sexual desire (demand) and are sexually capable (supply). Like any market, there are certain principles at work that help to explain the behavior of those transacting in the marketplace. Many economic concepts typically applied to traditional markets (elasticity, marginal utility, etc) can be applied to the SMP to help gain an understanding of human behavior. While the SMP can refer to the entire world, smaller sub-markets can exist within the global SMP which may exhibit unique or alternative characteristics.
For Christians, the SMP is typically limited to other professed Christians. This narrows the scope of the SMP considerably, but does not negate the overarching elements of human nature.