Clickthrough rate (CTR) is a ratio of the number of people who see your free product listing or ad to the number of people who end up clicking it. CTR is used to analyse how well your free listings, ads, and keywords are performing. The number of clicks that an ad receives divided by the number of times it is seen is known as CTR. The number of times an ad is seen is known as impressions. As an example, if the number of clicks is 5 and the number of impressions is 100 then the CTR will be 5 percent. Each keyword, listing, and ad has its own CTR. A high CTR is an indicator that users find your listings and ads relevant and helpful.