In the television industry's eternal search for younger viewers, USA Network has decided to emphasize comedy over crime. So far, however, few people in the ad industry are smiling.

The centerpiece of USA's prime-time lineup this fall season is reruns of the broadcast hit "Modern Family," which proved popular with a younger audience on the ABC broadcast network. TV networks, including USA, the top-rated U.S. cable channel, have found that group increasingly hard to retain.

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