Sex is cheap. Coupled sexual activity has become more widely available than ever. Cheap sex has been made possible by two technologies that have little to do with each other-the wide uptake of the Pill and high-quality pornography-and its distribution made more efficient by a third, the uptake of online dating. Together, they drive down the cost of real sex, have created a massive slow-down in the development of significant relationships, put women's fertility at risk, and have even taken a toll on men's marriageability. What the West has witnessed of late is not the social construction of sexuality or marriage or family forms toward different possibilities as a product of political will, but technology-driven social change. This revolution in sexual autonomy also ushered in an era of plastic sexuality and prompted the flourishing on non-heterosexual identities. This book takes readers on a tour inside the American mating market, and highlights key patterns that characterize young adults' experience today, including the early timing of first sex in relationships, overlapping partners, the hazards of online dating, frustrating returns on their relational investments, and a failure to link future goals like marriage with how they are conducting their current relationships. Drawing upon several large nationally-representative surveys, in-person interviews with 100 men and women, and the assertions of scholars ranging from evolutionary psychologists to gender theorists, what emerges is a story about social change, technological breakthroughs, and the unintended consequences of women's economic success. Sex and its satisfactions are becoming increasingly important in contemporary life. No longer playing a supporting role in enduring relationships, sex has emerged as a central priority in relationship development and continuation. But unravel the layers, and it is obvious that the emergence of "industrial sex" is far more a reflection of men's interests than women's.