Advertisement as Signaling
Advertising is the communication of a signal (information) with the express purpose of gaining advantage over one’s rivals in a competitive environment. That’s my definition of advertising in the broadest terms. In those terms, advertising is not limited just to the world that is human made. All sorts of life forms over evolutionary time scales have been in the business of advertising. In the natural world, advertising serves a very useful function, the end result of which is the astonishing appearance of beauty and diversity. A beautiful human face is not just an advertisement but also the result of successful advertising. Little wonder that beautiful people appear in advertising pictures.