Click-through Rate (CTR) is a metric used in online advertising & email marketing to measure the effectiveness of an advertisement or link in generating clicks from users.
It is calculated by: (Number of Clicks/Number of Impressions * 100)
If an advertisement receives 500 clicks & is displayed 10,000 times (10,000 impressions), the CTR would be calculated as follows: 500/10000*100 = 5%.
In layman’s terms, a 5% CTR means that out of every 100 people who see the ad, about 5 of them actually click on it to learn more or take action.