List Building: Single or Double Opt-In?

Single or Double Opt InI’ve been working on a few niches that are not related technology and Internet marketing, and as part of the project, I am collecting email addresses… as they always say – the money is in the list.

However, I did an experiment with regard to the method of collection of email addresses. Particularly, I tried both single and double opt-ins.

My original AWeber account has double opt-ins enabled. Due to AWeber’s strict policies, I was not able to create a mailing list that used only single opt-ins. The results weren’t fantastic.

I was curious if the double opt-in mechanism was the one causing the less than satisfactory results, so I went on to register a separate account, using single opt-ins. At the same time, being curious, I personally emailed a couple of the unverified leads from my first experiment to ask what actually happened.

Some of the replies I got were stunning.

One said that he didn’t receive the verification message… and another mentioned that he didn’t know that there was a need to verify (even though my notice to check the verification message is VERY prominent!).

On the other hand, not to what I expected, the single opt-in method work well. The leads were still responsive, and I cut my cost per lead 4 times.

I gave it some thought – that from a strictly business standpoint, single opt-ins should be the way to go. That probably explains why most Internet marketers use single-opt ins.

People are simply too lazy to get verified.

What’s your take on this?


  1. Hi Tan,

    Excellent study, and right you are!

    The “double optin” is mainly put in place to protect the email service…the is no “spam law” that requires double optin, as many people have tried to convey that there is.

    And yes, many times (many, many times) either people don’t receive the optin notice, or don’t recognize it, or don’t know to do it.

    Mark Hendricks

  2. My expirience with double opt-in vs. single opt-in is that around 70% more people convert. In onther words, never use double opt-in, its just too expensive in terms of users signed in.

  3. By the way when we are talking about opt-in and list building conversion – I see you require both first and last name in your Free eCourse, have you experimented or splittested on how it affects your signup vs. how active a list you get?
    On my site we only require email, as a splittest prooved that around 40% more signed up when only email was required.

  4. Thanks for the post. From what I understand it is always better to have verified opt-ins. I, personally, don’t want folks on my list that don’t there. In addition, IMO, how would you know if the person who owns the email address REALLY owns that email address. Know what I mean.

  5. Hey! Great study on the list building.

    Well, it made me comment.Yes single opt-in is much better than the double opt-in.

  6. HI
    i have tips for single opt :
    single opt in is that everyone who subscribes to your newsletter or ezine via the subscription form on your website will start receiving your messages instantly without any additional requirements. Once they fill in their name and email address and hit the subscribe button your auto responder messages will start being sent.

  7. Go with a custom database application and collect information from your registration or coregistration path as though it was a single opt in, then set an autoresponder which links back to the database (tracking the user) in case they optionally double opt in. If you need help customizing something like this or if you need opt in data feel free to ping me.

    Russell Rockefeller
    Opt In Plus Inc.
    1 Yonge St. Suite 1801
    Toronto Ontario Canada M5E1W7

  8. Internet marketing and any marketing for that matter, is the life blood of any business. But your advantage on the internet is huge, cause of the low cost and ease. (you can do it yourself) But you still have to work hard and put time into it…and we all know that nothing is for free in this world. (usually) Actually, I’m wrong, there’s tons of stuff for free on the internet, and you can also get a ton of traffic to your site for free, if you know how to play the game, work hard, and know how to market yourself. There’s tons of tricks and tips and I try to learn one everyday.

  9. I have tried both methods and prefer single opt-on. As with anything, there are advantages and disadvantages to both.

    Often, those of us who have been marketing with the Internet for any period of time become jaded by what we know. We can forget that there are masses of people coming onto the Internet each and every day. Some have no clue whatsoever about various ways to get on a list.

    With double opt-in you do have the advantage of a “cleaner” list. However, you also risk losing lots of people who have no clue what the double opt-in is and never confirm their confirmation.

    With single opt-in you risk more junk email addresses.

    After careful considerations on both sides of the issue, my choice is single opt-in.

    Kathleen Gage
    The Street Smarts Marketer

  10. Hi, I too have noticed this it seems to be about a 60/40 split in the list I am currently building thats 60% that dont confirm and 40% that do.

    Of course the main reason for preferring confirmed opt in is to make sure you have good defence should spam be claimed at a later date as they had physically submitted the request twice.

    Non verified leads do not provide you with such an audit trail and it is easier for a spam complaint to be upheld and that is something we all want to avoid.

    Being unkind it perhaps also weeds out the tyre kickers who only wanted your free offer in any case and ensures your sign ups have at least a couple of brain cells not too pc but true nonetheless.


  11. Hi,

    Can someone recommend an emailing service like Aweber that allows single opt in?


  12. For those who do bulk mailing should go for the double opt-in method. The mailing list generated by this is cleaner and does not have any junk email address which considerably reduces the load of email engine.

  13. I switched to Aweber with a substantial subscriber list and due to Aweber’s double opt in I lost more than half of my subscribers. I think the double opt in is confusing to most. Also, it was impossible for them to import my list from Excel -they were treating it like spam.