Click-Through Rate (CTR) is a key performance metric that measures the percentage of users who click on a link in an email, advertisement, or webpage after seeing it. CTR is calculated by dividing the number of clicks by the number of impressions and multiplying by 100. A high CTR indicates that the content is engaging and relevant to the audience, while a low CTR suggests a need for optimization. Marketers use CTR to evaluate the effectiveness of digital campaigns, including email marketing, paid search ads, and social media promotions. A/B testing, compelling call-to-actions (CTAs), and audience segmentation help improve CTR. CRM systems track CTR metrics to refine marketing strategies and improve conversion rates.