Mate choice strategies are a process of negotiation in which individuals make bids that are constrained by their status in the market place. Humans provide an unusual perspective on this because we can measure their explicitly expressed preferences before they are forced to make any choices. We use advertisements placed in newspaper personal columns to examine, first, the extent to which evolutionary considerations affect the level of competition (or market value) during the reproductively active period of people's lives and, second, the extent to which market value influences individual's willingness to make strong demands of prospective mates. We show that female market value is determined principally by women's fecundity (and, to a lesser extent, reproductive value), while male market value is determined by men's earning potential and the risk of future pairbond termination (the conjoint probability that the male will either die or divorce his partner during the next 20 years). We then show that these selection preferences strongly influence the levels of demands that men and women make of prospective partners (although older males tend to overestimate their market value).