If you have all the research, all the ground rules, all the directives, all the data - it doesn't mean the ad is written. Then you've got to close the door and write something - that is the moment of truth which we all try to postpone as long as possible.
David OgilvyNobody should be allowed to create general advertising until he has served his apprenticeship in direct-response
David OgilvyOn the average, five times as many people read the headline as read the body copy. When you have written your headline, you have spent eighty cents out of your dollar.
David Ogilvy