Blockbuster Video relies on humor in the campaign it broke last week, trying to turn a "routine" event, renting a video, into something special. One spot in the "Definitions" campaign discusses the phenomenon of "Narratim Verbatim," in which kids repeat a line from a movie-in this case "What's up, little pup?"-endlessly as they watch the tape 600 or 700 times. If only mom and dad had rented more than one video. The campaign is Blockbuster's first since Young & Rubicam
, New York, won the $140 million account in January.