Television encourages viewers to consume images that most people would otherwise not have access to in the course of a typical life. While this might sound like a benefit, television is not simply about seeing new and different things. It is also about selling. Television programming evolved hand-in-hand with consumerism, at first in its birthplace in America during the mid-20th century, but increasingly everywhere else in the world as well. In a way, television has spread the ethos of consumerism around the globe. It has also spread voyeurism, a more insidious form of consumerism, in the way it reveals what used to be private aspects of human life to public view. Television has normalized consumerism and voyeurism, and in turn these cultural preferences, encouraged by television, exert an influence over the medium, so that there is a reciprocity between television and society. The TV industries monitor the flow of this give-and-take relationship by sophisticated marketing surveys to tailor programs to what they perceive as the interests of their consumer-viewers. Many viewers are unaware that their habits are carefully monitored and that the television industries have created various market segments, or what they call "audiences," to buy and sell in the global marketplace, just like any other commodity. Although viewers think that they are sitting at home watching the tube, the tube is also watching them, and their viewing habits are traded in a marketplace that is still primarily driven by advertising.