Double Opt-In
A two-step subscription process requiring email confirmation before adding someone to your list.
Definition
Double opt-in requires new subscribers to click a confirmation link in a verification email before being added to your list. This extra step proves the email address is valid and the owner genuinely wants to subscribe.
While it reduces list growth rate, it dramatically improves list quality and deliverability.
Why It Matters
Single opt-in lists accumulate typos, fake addresses, and unwitting subscribers who never confirm interest. These lead to high bounce rates and spam complaints.
Double opt-in lists show higher engagement because every subscriber actively confirmed their subscription.
Examples in Practice
An online publication switches from single to double opt-in. Weekly signups drop 35%, but open rates increase from 22% to 41%, and unsubscribes fall 60%.
A SaaS company uses double opt-in for their newsletter but single opt-in for trial signups where immediate communication is essential for activation.