The media is important and there are commercials for business reasons and news and entertainment.

For media to become mainstream, it must appeal to many people. The values expressed must be attractive to the audience, otherwise it will not sell. Example of specific media - Television:

Television rates each show by the number of viewers. Shows that do not have a large audience are usually cancelled and then they can allow time for a new show. Successful shows are duplicated. For example, Star Trek was successful so it is the creation of many new Star Trek shows (Deep Space Nine, Voyager). Viewers decide which shows stay or leave. What makes a successful or unsuccessful show? Usually if the audience can identify with an actor, or situation, etc. the show will gain popularity. Special effects make shows more interesting; but, if the plot is not acceptable, the show is usually doomed.