Click-through rate reflects the ratio of which two elements?

Click-through rate (CTR) is a key performance metric used in digital marketing that measures the effectiveness of an advertisement. It specifically calculates the percentage of individuals who clicked on an ad relative to the number of times that ad was displayed, which is known as impressions. This ratio provides insight into how well an ad attracts users' attention and drives them to take action.

By focusing on the number of clicks an ad receives divided by the number of times it was shown, this metric allows marketers to gauge the relevance and appeal of their advertisements. A high click-through rate indicates that the ad is engaging and relevant to its audience, while a low rate might suggest that the ad needs improvement or better targeting.

The other options focus on different metrics or actions that do not directly align with the definition and calculation of click-through rate. For instance, some choices discuss actions taken by visitors or outcomes unrelated to clicks in the context of impressions and visibility, which are not the scope of what CTR measures.