Which metric is commonly used to measure the effectiveness of an ad campaign?

The click-through rate (CTR) is a widely recognized metric for assessing the effectiveness of an ad campaign, particularly in digital advertising. CTR represents the ratio of users who click on an ad to the number of total users who view the ad (impressions). A higher CTR indicates that the ad is resonating well with its audience, leading them to take action and click on the ad to learn more. This metric is crucial as it reflects the initial engagement of the audience with the ad content, serving as a strong indicator of relevance and appeal.

In the context of measuring ad performance, while other metrics like return on investment (ROI) provide insights into the overall financial effectiveness of a campaign and engagement rate (ER) measures the level of interaction beyond clicks, CTR directly quantifies the effectiveness in driving clicks. The cost per click (CPC) is more focused on the cost efficiency of gaining traffic but doesn't directly measure how effective the ad is in engaging viewers to click. Therefore, CTR stands out as an essential metric for gauging the success of ad campaigns in attracting initial audience interest.