Email open rate is the percentage of recipients who open your email campaigns. It’s a primary measure of subject line effectiveness, audience engagement, and deliverability.
Open rate is often the first indicator of whether your email content is being seen at all. Low open rates may point to poor subject lines, unengaged subscribers, or spam filter issues. High open rates mean your content is resonating at the inbox level, increasing the likelihood of downstream actions like clicks and purchases.
Open Rate = (Unique Opens ÷ Delivered Emails) × 100%. It’s tracked using a small tracking pixel that loads when the email is opened. Privacy changes (like Apple’s Mail Privacy Protection) can affect accuracy, so trends matter more than absolute numbers.
A DTC pet supply brand has a 15% open rate. By testing curiosity-driven subject lines and sending campaigns at optimal times for each segment, open rate improves to 24%, resulting in higher click-through and sales.
Open rate is not click-through rate. It also differs from deliverability rate, which measures how many emails land in the inbox.
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