Click-through rate (CTR) is a key performance metric used in digital marketing to measure the effectiveness of an online advertising campaign or an email marketing strategy. It is defined as the ratio of users who click on a specific link to the number of total users who view a page, email, or advertisement.
CTR is usually expressed as a percentage and is calculated using the following formula:
\[ \text{CTR} = \left( \frac{\text{Number of Clicks}}{\text{Number of Impressions}} \right) \times 100 \]
Where:
- Number of Clicks refers to the total number of clicks on the link, ad, or email.
- Number of Impressions refers to the total number of times the link, ad, or email was viewed.
A higher CTR indicates that the content is engaging and relevant to the viewers, while a lower CTR may suggest that the content does not resonate with the audience or that the call-to-action needs improvement. It is commonly used to evaluate the performance of online ads, email campaigns, and other digital marketing efforts.