Final answer:
A headline in an advertisement is critical for capturing readers' attention and sparking interest in the ad's content, engaging them throughout.
Step-by-step explanation:
An ad’s headline is designed to attract readers' attention and develop interest so that they will read the entire advertisement.
The headline serves as an overview to draw readers in, perhaps using an anecdote, a provocative question, or a compelling quotation. In crafting effective advertising, a powerful headline is crucial for engaging the audience and guiding them through the purpose of the ad, whether it's to persuade, inform, entertain, describe, or explain.