Half of Shopify stores run double opt-in. Only about 1 in 6 put it on their discount popup.

In late August I went through the public storefronts of roughly 2,000 US Shopify brands. Not the backends, just what any first-time visitor's browser gets: the homepage, the popup that fires, the signup form that renders, and the published form configuration every Shopify store serves to its visitors.

The question I wanted answered wasn't whether stores run double opt-in. Plenty do, and on most lists it's harmless. The question was how many have it on the form where it’s costing them money: the discount popup. A visitor is promised 15% off, hands over their email, and then gets told to go find a confirmation email before the code appears. A lot of them never do, and the store never sees how many signups they’re actually losing.

The first number below makes it look like that's happening everywhere. It mostly isn't, but where and how it does happen are things every Shopify store operator should understand.

The first number: double opt-in is everywhere

938 of 1,952 stores (48%) run at least one signup form whose own success screen tells the new subscriber to go check their email and confirm. That is double opt-in, running on about half the stores I looked at.

One note on what that number is. I counted stores where a form's own copy declares a confirmation step. That's a positive-only signal: if the success screen says "check your email," I know the list runs double opt-in. If it doesn't say that, I don't know either way. So 48% is a floor, and the other 52% are not "stores on single opt-in." They're stores where I couldn't tell.

Taken alone, that number would suggest half of Shopify is stalling its welcome offer behind a confirmation click. It isn't, because where exactly the double opt-in lives matters more than whether it exists on the site.

The second number: it's mostly not on the popup

1,289 of the 1,952 stores (66%) had a discount popup fire on a first visit. Among those 1,289, 677 (52.5%, about half) run double opt-in (DOI) somewhere on their signup stack, but not necessarily on the discount popup. Could be the footer box, a back-in-stock form, an old launch form.

The popup itself is a different story. Of the 1,289, I could trace 935 popups end to end, from the creative on the screen to the specific form and list behind it. Of those 935, 168 had the confirmation step on the popup's own form. That's 18%, about 1 in 6. That's the population where a visitor is promised a discount, types in an email, and gets told to go click a link before the code shows up.

The other 354 popups run on third-party tools, where the popup and the list live in different systems and I can't see from outside whether a confirmation step sits between them. Counted against all 1,289, the DOI-gated discount popup share is 13%, about 1 in 8, and that's the hard floor. If the third-party tools gate at a similar rate to Klaviyo's form builder, an assumption I can't verify, the true number sits around 1 in 6. Well above 1 in 8 either way, but nowhere near the half of discount-popup stores that have double opt-in somewhere.

So the typical store with double opt-in and a discount popup is not gating the discount. It has confirmation on some lists and not on the one behind the offer. Whether that was an active decision or an accident is the question, and I'll come back to it.

What the gate does to a welcome offer

For the stores in that 1 in 6, here's the sequence. A visitor lands, the popup fires, it offers 15% off for an email. They type it in. Instead of a code, they get a screen that says "check your email for a confirmation message." The code is behind a link in an email they now have to go find and click.

Some of them do. Plenty don't. They came for a discount, they held up their end, and now there's a second step that wasn’t mentioned beforehand. They close the tab, or the confirmation email lands in a promotions folder and sits there.

Every one of those people is two things at once:

1. 01A promised discount you never delivered.
2. 02A subscriber your welcome flow never greets. Unconfirmed profiles don't enter the welcome series, which for most stores is the best-converting email they send.

And none of it shows up in your dashboard as a problem. Confirmed subscribers look fine. Unconfirmed ones mostly don't exist from the reporting's point of view.

One that stuck with me: a small handmade-goods studio with a 15%-off welcome popup that should be doing real work for them. The popup was locked to the homepage, so anyone arriving from an ad onto a product page never saw the offer. And the list behind it ran double opt-in, so even the visitors who did see it and did type in their email still had to go click a confirmation link before the 15% showed up.

Decision or accident

Back to the half-versus-1-in-6 gap. Most stores with double opt-in somewhere have it on a form like the footer box, where nothing was promised, and not on the popup, where a discount was. That's the right split. The question is whether anyone chose it.

Here's why I doubt it in most cases. New Klaviyo lists ship with double opt-in turned on. So a store where the footer list has it and the popup list doesn't is usually a store where one of two things happened: someone deliberately went into the popup's list settings and switched it off, or the two lists were created at different times by different people, and only one of them touched the setting. The former is a purposeful decision, the latter is just luck.

The key difference is what the owner/operator knows. If the popup's list was set up that way on purpose, the owner knows the rule: no confirmation step on a list that promises a discount. They'll apply it to the next offer form they build. If it was luck, that rule’s not getting applied consistently. The next discount form gets a new list, the new list gets Klaviyo's default, and that store joins the 1 in 6 with ill-advised gating without anyone noticing.

When double opt-in is the right call

I'm not against it. It makes sense when:

• Your list attracts bot signups or junk addresses at a rate that hurts deliverability. A confirmation step is a hard filter, and if you've watched bounces climb from garbage signups, it earns its keep.
• You operate somewhere that expects it. Some markets and their associated legalities lean toward explicit confirmation. If that's your situation, it comes with the territory.
• The form isn't offering anything. A footer box that says "join the list" has no promised code to stall. That’s exactly where most of the stores with DOI seem to have it, and it's a reasonable place for it.

The problem isn’t double opt-in. The problem is double opt-in on the one list whose front door is a discount, set by whoever built the form and never looked at it again.

What to check on your own store

Two minutes, easy to do on your own.

1. 01Open your store in a private window and sign up through your own popup with a fresh address. Read the success screen. If it tells you to confirm by email, your discount is gated.
2. 02Do the same through the footer box, and any other signup form on the site. Note which ones ask you to confirm and which don't.
3. 03Compare the list. Every list with confirmation on should have a reason you can say out loud. The discount popup's list almost never has one.
4. 04Fix the forms that don't need DOI. In Klaviyo it's a per-list setting.

Why I looked at 2,000 stores to say this

"Turn off double opt-in" has been floating around Shopify circles for years. So has "keep it on for list hygiene." Usually neither side has the numbers, but they’re both partially correct: many stores keep it on somewhere and keep it off the popup, which is the sensible split, whether or not they meant to. The ones who didn't make that split are a minority, about 1 in 6. If you're in it, the fix is one setting.

If you want to know whether your setup looks healthy, that's what I’m here for. Reach out and I’ll be happy to take a look.

Matt

Methodology

Between August 19 and September 2, 2026, I analyzed the public storefronts of 1,990 US Shopify brands in a single pass; 38 could not be assessed (password-locked, unreachable, or broken) and are excluded from every figure rather than counted as zeros, so every number in this post uses the remaining 1,952 stores as its base. For each store I rendered the homepage and key pages the way a first-time visitor's browser would, letting popups fire and reading the signup forms that actually appeared, and read the publicly served marketing configuration every storefront exposes to its visitors: published signup-form definitions, email and SMS vendor tags, and public DNS records. Nothing was accessed behind a login, no forms were submitted, and no customer data was touched. A single visit can miss popups gated by geography, device, or return-visit rules, so fire rates are stated as first-visit figures. Double opt-in detection is positive-only: a store is counted when a form's success-step copy declares an email confirmation step. Absence of that copy does not indicate single opt-in. Popup-level gating was measured only where the fired popup could be matched end to end to a published Klaviyo form (935 of 1,289 offer popups); popups run by third-party vendors could not be assessed, so the 13% figure against all 1,289 is a lower bound and the 18% figure against the 935 measurable popups is the best estimate. "Discount popup" in this post includes any popup displaying a visible offer, including free shipping and giveaways.