What is the primary characteristic of a roadblock ad in digital marketing?

The primary characteristic of a roadblock ad in digital marketing is that it occupies the entirety of the screen before any page content is displayed. This type of ad is designed to capture the user's attention fully by blocking access to the content of the website until the ad is dismissed. The approach ensures maximum visibility for the advertiser, as users are compelled to view the ad in its entirety before proceeding. This format is effective for brand messaging, promotions, or announcements, as it significantly reduces the likelihood of users bypassing the advertisement.

In contrast, other options describe different ad formats that do not encapsulate the all-encompassing nature of a roadblock ad. For instance, video ads are targeted specifically for video content and are not necessarily blocking page content. Similarly, banner ads are usually placed in specific areas of a webpage rather than covering the entire screen, and pop-up ads interrupt user interaction but do not typically preclude access to complete content like a roadblock ad does.