Opt-in is the moment permission is granted — the difference between a subscriber who wants your emails and a stranger who doesn't. It's what makes email marketing both effective and compliant.

What are the types of opt-in?

Single opt-in adds a subscriber as soon as they submit a form. Double opt-in requires them to confirm via a follow-up email before they're added. Double opt-in yields a cleaner, more engaged list.

Why does opt-in matter?

Opted-in subscribers engage more and complain less, which protects deliverability. Explicit opt-in is also required or strongly recommended under privacy laws like GDPR.

Opt-in best practices

Make consent clear and unchecked by default, set expectations about frequency and content, and deliver on the promise you made at signup.