There is some debate in internet marketing circles about the right way to do email list building.
Basically there are two main methods for building a mailing list – opt-in and opt-out.
Opt-out is when you say “I will send you emails that I think you will like until you tell me you don’t want to receive any more”. Opt-out marketing is bad, and it’s a good way to make your audience angry with you.
Opt-in is when you say “You can voluntarily sign up here to receive my emails”. Opt-in marketing is good, but we take it one step further and break opt-in up into two sub-methods.
Double opt-in is when you say “You can voluntarily sign up here to receive my emails, AND you’ll then get an email asking you to confirm your registration so that I can be 100% sure you really want to receive email from me”.

Single opt-in is almost the same but it skips the confirmation process and adds the new subscriber to the list as soon as the signup form is submitted.

In an email marketing course I’ve been developing I wrote:
Single opt-in is open to abuse because you can be added to a list by someone else without your knowledge. Double opt-in is the standard amongst ethical email marketers.
Double opt-in is good for EVERYONE. It’s good for your subscribers, because they don’t receive email they don’t want. It’s good for you, because you don’t have people on your list who don’t REALLY want to be there. And it’s good for your email service provider, because they have to deal with fewer spam complaints.
Bottom line, if your list building doesn’t include a double opt-in step, you’re doing it wrong.
But a few weeks ago I signed up to the newsletter of one of the A-listers in the Third Tribe community, and was surprised when I received neither a confirmation message nor a welcome message. Initially I dismissed it as a delay with the email service provider, but after a few days I realised I still hadn’t received either message and decided to ask the person about their signup process.
As it turns out their list is single opt-in, which was quite a surprise for me. However I had a brief conversation with one of the people working for their email service provider, DJ Waldow of Blue Sky Factory, who is of the opinion that single opt-in is in fact the better method to use.
Here is what DJ says on the topic:
If someone wants to subscribe to email communications from you and/or your company, why would you make it difficult?
As they say in sales, “stop when they say yes.” A double opt-in is the equivalent of someone raising their hand for more information and you replying with “are you sure?”
Also, a lot can go wrong from a delivery perspective on the confirmation (double opt-in) email. It could get blocked, flagged as spam by the ISP or corporate filters, deleted or ignored by the subscriber, etc. Then, you have someone who wanted to opt-in who is not getting those emails. FAIL, right?
When I asked if there were any specific scenarios where double opt-in would be more appropriate, he answered:
Hmmm. No. Truthfully, if you are worried about bots signing up, you can do things on the front end to prevent that. Same goes with folks putting in the wrong email address.
The key is setting proper expectations around content and frequency up front, during the signup process (and delivering on that promise). Also, continue to ensure that your emails are valuable.
DJ and I have been on the same side of some spam related discussions in recent months so his opinion is not one that I’m willing to disregard.
When I think a bit more about it perhaps what was more surprising than the A-lister using single opt-in was the lack of an immediate welcome message. I’ve joined other single opt-in lists before (you never know if they are single or double until you signup) and for all of those the first autoresponder message arrives immediately, so there is no confusion about whether the signup process worked.
For the A-lister it is entirely possible that their first newsletter could arrive in my inbox weeks after I signed up (it has been about 2 weeks already with no newsletter yet) and as a result a new subscriber could forget they had signed up and make a spam complaint.
But at the end of the day I think I stand firmly in the double opt-in camp for now.
What about you? Are you a single or double opt-in list builder?
Image Credit: Flickr






There’s no question, double opt-in just feels the right thing to do. Although single opt-in is open to abuse, doubles will reassure visitors what they are signing up (as long as each email confirms what the visitor is signing up for – a bit like a scent).
The only down-side to doubles is if the confirmation email gets binned in the spam folder by accident, the visitor is likely to forget and you don’t get the opt in.
Dan
That is a risk. I see some bloggers will redirect new subscribers to a page with the confirmation instructions including a “Check your spam folder just in case it went there, and btw now would be a good time to whitelist me” type instruction.
Paul – Good point, but who ever reads that page? Really? I don’t…
I am against useless emails. I don’t really like confirmation emails. As long as the unsubscribe process is quite easy then inadvertent or spam sign-ups should not be too much of an inconvenience.
Occassionally I use the double signup to my advantage when testing email sign up forms, but generally, I don’t find that many people fake my sign up and I find a confirmation if sign up or unsubscribe totally unnecessary.
Hmmm, my experience is that unhappy subscribers can be quicker to hit the Report Spam button than click an unsubscribe link though.
Double opt-in at least gives you some shield from the accusation of being a spammer.
Double opt-in for me.
I agree that removing friction is good, but it’s not just fake sign up bots that are the problem, it’s also people signing you up for their email newsletters without your permission. Meeting someone at an event isn’t permission.
I believe it also helps with deliverability.
And absolutely, there should be a welcome message (mine also includes a sample newsletter). It makes people feel, well, welcome, and gives them a taste of what they’ll be receiving in future newsletters.
Yeah I think it was the absence of double opt-in PLUS the absence of any welcome message in the example in the post that really set off my train of thought here.
Paul, I also feel strongly that double opt-in is the best way to go. It’s important to protect potential customers and my reputation.
My reputation is definitely a big factor in my decision to go double. My other blog is all about enterprise email systems and spam is a sub-topic of that so I want to be 100% clean in my own email marketing there.
I’m pro-double. It just makes me feel better to think people I mail to put some conscious thought/effort into joining the list.
Once I understood the mechanics of the two methods double was definitely something that made me feel more comfortable sending emails.
Definitely a double opt-in guy! I contemplated making the switch a while ago but read too many horror stories of high spam labeling. Anyway if you are doing it right, then having a double opt-in shouldn’t effect your results that much anyway.
I agree, a well executed double opt-in never feels like a pain to go through.
Good to see you around Tom.
Paul:
Great post! As mentioned in my email to you, I blogged about it today (with some link love/juice back here, of course).
Why Double Opt-In is a Terrible Idea – http://ar.gy/kP
I think some of those who commented here didn’t read the entire post. I’ll comment back to them individually!
DJ Waldow
Director of Community, Blue Sky Factory
@djwaldow
Hi Paul,
Thanks for the thought-provoking post. I am a few days behind in my Third Tribe forum stuff and just read your thread there this morning.
I’d never really thought much about this. Of course, I have a pretty small list, too, and I don’t want to lose the people I have, so do you have any thoughts on how to change mid-stream? I am getting ready to switch my list from Constant Contact to aWeber or another service, and might as well explore this issue as long as I am making the other change.
Sean
Sean, switching providers will lose you some subscribers. Its a bitter pill but long term you’ll bounce back, and the subscribers you do keep will be your most loyal and committed ones so you get to keep the quality anyway.
I’ve just checked and Aweber does let you switch a list between double and single opt-in. If thats something you want to test out sure, but with less than 10% unverified on my lists I’ve never found the double opt-in to be at all detrimental to my list growth.
Why complicate things for the small percentage of people who be signed up to your list by accident. I think most people are intelligent enough to understand they are adding themselves to your email list by putting their name and email in the boxes and hitting submit or subscribe. Let them sign up and give them the information as quickly as you can. If double opt in is so great why not triple opt in? Are you really, really sure you want to let me send you emails!!!!
On the flip side, how do you defend yourself from spam complaints if you aren’t using double opt-in?