A good headline can be the difference between 1,000 people and 1,000,000 people reading something.
Eli Pariser - Upworth
A good headline can make an advertisement good even if the picture is poor.
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 - Ogilvy, Mathers