But first, a little background on single opt-in and confirmed (or double) opt-in. Let's say you have a form on your site that's pointing to a subscribe list. If it's single opt-in, it will accept new subscribers immediately after the form is submitted. However, confirmed opt-in lists include an interim step, which usually involves an email being sent to the subscriber's email address first. Once a link in the email is clicked (thus confirming that the email address is valid), the subscriber is added.
Weighing up the pros and cons
There are fairly straightforward advantages and disadvantages to each approach. While single opt-in is less complicated than confirmed for both email senders and subscribers, it does open up subscriber lists to collecting invalid email addresses - either as a result of honest mistakes, or spambots. On one end of the scale, these invalid email addresses can be a mild annoyance, but on the other, they can be an expensive problem, impacting your campaign metrics, delivery rates and bottom line.
That said, the commitment that goes into confirming twice-over can deter would-be subscribers, even if it is a good measure of future engagement. But then, if a would-be subscriber never receives the confirmation email - say, because it gets stuck in spam - then they won't get a chance to receive future campaigns.
Is there a 'correct' approach?
Given these two sides, it's easy to see why folks may be either unsure, or passionate about whether their approach is the correct one. From our perspective, they're both valid - although we see the value in going confirmed, especially in regards to boosting engagement rates and keeping subscriber lists clean. So at this point, we'd like to turn the discussion over to you - do you use single, or confirmed opt-in for your lists? Why? Let us know in the comments below.