Click-through rate (CTR) is the ratio of users who click on a specific link to the number of total users who view a page, email, or advertisement. It is commonly used to measure the success of an online advertising campaign for a particular website as well as the effectiveness of email marketing and email campaigns.

The formula for CTR is:

click-thru-rate

Click-thru rates vary depending on platform, industry, keyword competitiveness, and other factors.