Which metric shows how many people may be interested in your ad based on your criteria?

The correct metric that indicates how many people may be interested in your ad based on your criteria is potential reach. This metric estimates the total number of unique users who might see your ad, provided they fall within the parameters you set for targeting, such as demographics, interests, and behaviors. It gives marketers an idea of the size of their audience and helps them understand the potential effectiveness of their advertising strategies.

Potential reach is particularly valuable for assessing the scale of advertising campaigns and planning audience targeting methods. It allows advertisers to gauge how well their campaigns can connect with individuals likely to be interested in their offering, thus informing decisions on budget allocation and message tailoring.

Unique impressions refer to the number of times your ad is shown to a unique user but do not necessarily indicate interest in the ad. Cost per click is a metric relating to how much you are paying for each click on your ad and does not reflect potential audience interest either. Engagement rates measure interaction levels with the ad but only provide insights after the ad has been displayed, rather than indicating potential interest before the ad runs.