Click-Through Rate (CTR) is a metric used in affiliate marketing to measure how successful an ad campaign is. It is calculated by dividing the number of clicks an ad receives by the number of impressions it received. For example, if an ad receives 10 clicks out of 1,000 impressions, its CTR would be 1%.CTR is an important metric in affiliate marketing because it helps marketers understand how effective their campaigns are in driving engagement and conversions. It can also be used to compare different campaigns and determine which ones are performing better. For example, if two ads have a similar number of impressions but one has a higher CTR, it suggests that the audience is more engaged with the higher-CTR ad and more likely to take action. This can help marketers adjust their campaigns and focus on the ads that are more likely to drive conversions.