What is the difference between CTR and unique CTR?

Click-through rate rate (CTR) is the number of clicks your ad receives divided by the number of times your ad is shown.

Unique click-through rate rate (Unique CTR) is the number of clicks on an ad, divided by the number of people reached.

To calculate the CTR and Unique CTR, you can use the following formulas:

CTR = Clicks/# of impressions

Unique CTR = Individual clicks/people reached