What is the measurement standard for ad units expressed in?

The measurement standard for ad units is expressed in pixels because pixels are the basic units of measurement in digital graphics and display technologies. In the realm of digital advertising, understanding the dimensions of ad units in pixels is crucial, as it helps ensure that ads are displayed correctly across various devices and screen resolutions. Pixels provide a standardized way to define the size of an ad, allowing for consistency in how ads appear on different platforms and environments.

While other units like centimeters or inches may be relevant in print advertising or physical media, they do not apply to the digital landscape where screen size and resolution can vary dramatically. Milliseconds can be relevant when discussing loading times or ad viewability metrics, but they do not pertain to the actual physical dimensions of ad units. Therefore, measuring ad units in pixels is essential for optimizing visuals, layout, and overall advertising effectiveness in a digital context.