GuideDouble opt-in trades subscribers for certainty.
That is the whole decision. Everything else is working out whether your list is one where the trade pays — and for one very common kind of popup, it does not.
Single versus double, on five axes.
Two of them favour single. We ship both, so we have no reason to pretend otherwise.
| Single opt-in | Double opt-in | |
|---|---|---|
| How it works | The address is subscribed the moment the form is submitted. | The address is provisional until the person clicks a link in a confirmation email sent to it. |
| List size | Everyone who submitted is on the list. | Smaller — some share of people never click, and a portion of that share genuinely meant to subscribe but never opened the confirmation. |
| Address quality | Typos, throwaways and other people's addresses all get through. | A confirmed click proves the mailbox exists and that its owner wanted this. That is the entire point. |
| Evidence of consent | One event: the submission, logged by you. | Two events, the second of which happened in the subscriber's own mailbox. Much harder to dispute. |
| Time to first email | Immediate — the welcome offer lands right away. | Delayed by however long the confirmation takes, which is where discount-code flows tend to leak. |
Three times single opt-in is the right answer.
The section a double-opt-in page is not supposed to have.
The offer is a discount code needed right now
A visitor who wanted 10% off this order will not wait for a confirmation email, find it, click it, and come back. The confirmation step sits directly across the path to purchase. This is the strongest argument against double opt-in and it is a commercial one, not a technical one.
Your volume is too low to see the benefit
The deliverability case for double opt-in is a statistical one about complaint rates across large sends. A store sending to a few thousand people will feel the list-size cost immediately and may never observe the benefit.
Your platform already suppresses hard bounces well
Much of what double opt-in protects against — dead addresses degrading your sender reputation — is also handled by a platform that suppresses aggressively after the first send. That is a partial substitute, not a full one, and it does nothing for the consent-evidence side.
How this works in BetterPopup.
Opt-in type is a per-campaign setting, not an account-wide one, so the discount popup on a product page can be single while the newsletter signup in the footer is double. With double selected, the address stays provisional until the confirmation link is clicked, and only then does it sync to whichever of the 6 connected providers you use — so unconfirmed addresses never reach your ESP and never count against its contact limits.
Double opt-in, answered plainly.
Starting with the one everybody gets wrong about GDPR.
A two-step subscription process. Someone submits their address, then receives an email asking them to confirm; they are only added to the list once they click the link in it. Single opt-in skips the second step and subscribes on submission. The confirmation click is what makes the difference — it proves the mailbox is real and that the person holding it actually asked for this.
No. GDPR requires a freely given, specific, informed and unambiguous indication of a person's wishes by a clear affirmative action. A single opt-in form with clear wording can satisfy that. What double opt-in gives you is stronger evidence that it happened — which matters because under GDPR the burden of demonstrating consent sits with you. Some national regulators have historically encouraged it; that is a recommendation, not the text of the regulation. Not legal advice.
Yes, in raw numbers, and anyone who tells you otherwise is selling something. Some proportion of people who submit will never confirm — they mistype the address, the confirmation lands in spam, or they simply move on. The argument for it is not that the cost is imaginary but that the subscribers you lose are disproportionately the ones who would never have opened anything.
It removes two things mailbox providers react badly to: addresses that do not exist, and recipients who never asked. Both push complaint and bounce rates down, and those rates are a significant input to inbox placement. We are not going to quote a percentage improvement — the published ones all come from vendors measuring their own customers, and the effect depends heavily on how bad your acquisition was to begin with.
Double, if the signup is for a newsletter or ongoing content, if you send to a large list, or if you operate somewhere you may have to evidence consent. Single, if the popup offers a discount code the visitor wants applied to the order they are in the middle of placing — a confirmation step there costs conversions on the way to a purchase. Many stores end up running both, split by campaign, which is the sensible answer more often than either absolute.
Who is asking, what they will get, and one obvious button. Send it immediately, from a sending domain that matches the site, with a subject line that reads like a confirmation rather than a promotion — a clever subject here suppresses the open you actually need. If the signup promised a discount code, the confirmation is where it should be delivered, which turns the extra step into the reward rather than an obstacle before it.
You can start applying it to new signups immediately, and that is normally what people mean. Retroactively re-confirming an existing list is a different and much riskier operation — a re-permission campaign typically loses a large share of the list, and unengaged recipients are exactly the people least likely to open the email asking them to confirm. Do it when you have a specific reason, not as routine hygiene.
Source: Regulation (EU) 2016/679 (GDPR), Articles 4(11) and 7 — EUR-Lex