Understanding how to estimate the number of consumers the advertiser is reaching with his newspaper advertising program. Understanding how newspaper advertising is structured, priced, and sold. Understanding how the advertiser can get better results from newspaper ads by reducing the size of his newspaper ads and adding Radio to the advertising program. And it's costing him at lot more money to achieve increasingly diminishing results. He probably thinks that newspaper is still the best place to advertise, and he undoubtedly believes that he has to be there because most of his competitors are.
Perception is reality in the mind of the beholder.
Your job will not be to try to talk him out of advertising in the newspaper, because that approach is contrary to his beliefs and in direct conflict with his advertising paradigm. Confirm that his newspaper advertising is working, but perhaps not as well as he might like. Persuade him to agree that he could be getting better results if his advertising could reach more of the right consumers more often. Prove to him that adding Radio to his advertising program can help improve those results without increasing his costs. RAB will supply you with Newspaper Performance Reports for any audited paper.