Which of the following is a key component of display advertising?

Banner ads are a key component of display advertising because they are specifically designed to visually communicate an advertising message to users on web pages. Display advertising involves using graphical elements such as images, videos, and animations to capture the attention of potential customers. Banner ads, often placed at the top, side, or within the content of a webpage, are intended to drive traffic to the advertiser's site by encouraging users to click on them. This format allows advertisers to leverage creative design and brand visibility in a way that is engaging for the audience.

In contrast, social media posts, email newsletters, and search engine listings serve different purposes in the digital marketing landscape. Social media posts generally involve content shared on platforms to engage audiences organically or through paid promotion, but they do not encompass the visual, graphical nature of display advertising. Email newsletters focus on direct communication to subscribers, providing information or promotions without the visual ad format typical in display advertising. Search engine listings, while crucial for online visibility through SEO, relate to textual search results rather than visual display methods. Thus, the unique characteristics and functionalities of banner ads make them an essential part of display advertising.