Use single opt-ins to increase the size of your email list.

The simplest way for someone to become a subscriber is through a single opt-in signup process. It maximizes both the size and total engagements of your email list.

People are pretty much evenly divided in the debate between single opt-in and double opt-in (53.5% vs 46.5%, respectively). Using a single opt-in means that people become subscribers by simply entering their email addresses — no confirmation is required. This minimizes signup barriers and failure points, which are responsible for 20–40% failure rates in double opt-ins. Single opt-ins also produce higher overall engagement. The downside? They do all this at the expense of quality. But you can safeguard your list's quality by requiring users to enter their emails twice, validating addresses with tools like BriteVerify and Fresh Address, and periodically removing subscribers that don't engage with your emails. Even if you prefer double opt-ins, single opt-ins can still be useful in scenarios where the user has already been validated in other ways (like making a purchase). Before implementing, look into relevant laws, as some industries and localities don't allow single opt-ins. Up next: Double opt-ins.