１７、The following appeared in a letter from the manager of a rock band named Double Rice. "One year ago, tickets for Double Rice’s concerts in stadiums around the country took, on average, at least 24 hours to sell out, if they sold out at all. But the band has been enjoying a surge in nationwide popularity among 14 to 25 year olds, and the 30,000 tickets for a recent concert in Megalopolis sold out in 12 minutes. Clearly the ticket sales in Megalopolis are a result both of the band’s increased popularity and of the advertising campaign run in Megalopolis by the Ad Lib advertising agency. Thus, in order to ensure that the band’s success in Megalopolis is repeated across the country, the band should hire Ad Lib to duplicate the Megalopolis ad campaign on a nationwide scale."