Media assume their form and substance under the pressure of competition—more for advertising than for audiences. As advertisers define their markets in terms of particular target groups, media accommodate them by becoming more specialized. Advertisers do not act in concert to exert their collective economic weight. However, in pursuing their individual and separate interests, they tend to play by the same rules. Advertisers rarely try to buy journalists to slant news in their favor; more often they try to suppress news they don't like. They are sensitive about the environment for their messages and edgy about controversy. When advertisers yield to vigilante pressure, media producers veer toward self-censorship. Advertisers shape content directly when they sponsor broadcast programs. They shape content indirectly—as in the case of televised sports—by supporting media that meet their marketing requirements. The virtual end of local press competition shows how advertisers determine the life and death of media, with serious consequences for society.