what is the purpose of putting a headline in an advertisement?

2 answers

A headline calls the readers' attention to the ad.
A headline shows you what information is really important--usually the company name, or sometimes a memorable slogan, the date of a sale, or a new deal going on. This is why the nitty gritty is often put in small print at the bottom, because the company doesn't want you to know that the sale is only on Brand X of sweaters for example, but it wants you to come for a sale.