They come to your office with a shoeshine and a smile.
Advertising is one of the basic tools of the retail business.
This article won't answer all your questions. Every market, every advertiser is different. What it will do is provide you with the questions to ask so that you can pry the answers out of the parade of media salespeople who are knocking on your door, presentation in hand. Each has its own strengths and weaknesses. Most cities today are one-paper towns.