The average email click-through rate refers to the percentage of recipients who click on a link or call-to-action within an email. It is a measure of the effectiveness of an email campaign in engaging and motivating readers to take action. A higher click-through rate indicates a more successful email campaign, as it shows that a larger portion of the audience was interested and engaged enough to click on the provided links. This metric is commonly used by marketers to track the performance of their email campaigns and make informed decisions for future campaigns.