What is a "Unique Device"?

A Unique Device refers to a specific device (such as a computer, smartphone, or tablet) that has been exposed to a copy of a Message. In other words, it is a device that has been shown the advertisement. The concept of unique devices is used to measure the reach and effectiveness of an advertising campaign, as it helps to ensure that the same device is not counted multiple times in the same campaign. For example, if a Message is displayed on a website that a viewer accesses on their smartphone and then again on their computer, both views will be counted as separate unique devices.