Which of the following would least likely improve a campaign's click-through rate?

Increasing ad impressions refers to showing the ad to a larger audience or more often to the same audience, which does not inherently ensure that the ads will be more appealing or relevant to those viewers. Higher ad impressions could lead to more clicks in certain circumstances, but if the ads are not effectively targeted, engaging, or visually appealing, simply increasing the number of times an ad is displayed is unlikely to translate into a significant improvement in click-through rate.

In contrast, improving ad targeting enhances the likelihood that the ads reach individuals who are genuinely interested in the products or services being advertised, which can lead to a higher click-through rate. Similarly, using compelling ad copy captures attention and encourages interaction, while creating visually appealing graphics attracts users and makes ads stand out. All these elements are designed to engage potential customers, resulting in a greater likelihood that they will click on the ad. Thus, while increasing impressions is a strategy often employed, it is the least effective in directly enhancing click-through rates without addressing the quality of the ad content and its relevance to the audience.