The first task of an outreach marketing campaign is to attract attention by interrupting someone from whatever they are doing and thinking about.
The impact of the headline is critical.
A great headline will get the marketing piece read.
A good headline might enter the subconscious rather than the conscious mind. It helps with long term awareness of the problem and solution but it may not lead to the response the marketer wants.
A nondescript headline means the advertisement or other type of marketing contact is ignored.
Quite simply, a great headline will make or break many marketing campaigns.