View-through is a metric or a measurement technique that is used in digital advertising to track and evaluate the effectiveness of an ad that was not clicked on, but that was seen or viewed by a user. View-through is typically used for display or video ads that are served through an ad server or a tracking pixel, and that have a visual impact on the user, even if the user does not interact with the ad or the landing page. View-through is calculated as the number or the percentage of ad impressions that were viewed by the user, within a certain period of time or a certain distance from the ad, and that were later attributed to a conversion or an engagement. View-through is an optional and complementary metric to click-through rate (CTR), and it is used to assess the impact of an ad on the user, the brand, or the behavior, beyond the direct response or the immediate action.