Interactive Advertising Bureau (IAB) Digital Advertising Certification Practice Test 2025 - Free Digital Advertising Practice Questions and Study Guide

The definition of a viewable impression as stated by the MRC (Media Rating Council) confirms that for an impression to be considered viewable, at least 50% of the ad must be displayed within the user's view for a minimum duration of at least 1 second.

This metric is critical in digital advertising as it establishes a standard for evaluating the visibility of ads. It recognizes that advertisers want to ensure their ads are not just served but actually seen by users, which is crucial for effective brand messaging and engagement. By setting this benchmark, the MRC aims to enhance the effectiveness of digital advertising by focusing on the actual user engagement with the ad content rather than mere delivery counts.

The other options fall short of the MRC's criteria either by not meeting the percentage of the ad visible for the required time or defining impressions in ways that do not account for visibility, which is central to understanding what constitutes an effective advertising interaction.