A brand launches a campaign with Carousel ads on Pinterest aimed at boosting clicks, and the media planner must determine which metric best evaluates the success of this campaign. Given the campaign's goal, which metric should be prioritized to assess its effectiveness?

Engagement is the best metric because the campaign's goal is to boost clicks. Engagement metrics, such as click-through rate (CTR) and outbound clicks, directly measure user interaction with the ad, which aligns with the objective of driving clicks. Impressions only indicate how many times the ad was displayed, not whether users interacted with it. Video Completion Rate (VCR) is irrelevant for Carousel ads, which are image-based and don't involve video playback. Add to cart is a conversion metric that occurs further down the sales funnel; while ultimately desirable, it's not the primary, immediate goal of "boosting clicks.