You may be wondering about double opt-in. This type of opt-in entails a person subscribing and then being sent an email asking them to confirm the desire to subscribe, usually by clicking on a confirmation link in the email. Although double opt-in gained momentum years ago, deliverability and usability issues with getting that confirmation email to the inbox and clicked have caused many to move away from it. In fact, only 3 percent of major online retailers use a double opt-in subscription process.
Many clients using a double opt-in process have a black hole of data for those who are not completing the second stage of the double opt-in process. This means often there are many would-be email subscribers who fail to complete the second step for one of many reasons and, therefore, are not in the database but may not know that. Ensure that you can identify where the “forgotten email subscribers” data resides and make sure the second step email goes out without a hitch.