A conversion rate is the percentage of your subscribers that follow your call to action in an email marketing campaign.
For example, if you send an email to your subscribers with a call to action that reads Buy now, the percentage of your subscribers that make a purchase through the link provided is your conversion rate. Other examples of calls to action which can be measured as conversions include signing up for a newsletter, registering for an event, or simply clicking a link.
A conversion rate is an important measurement of your email campaign's success.
Email Glossary