Klaviyo Pop-Up Not Working? Why Your List Growth Quietly Stopped

Picture this. In May, your sign-up pop-up was seen 25,000 times. In June it dropped to 13,000. By July it was showing fewer than 400 times. Nobody changed the design. Nobody turned it off. It just quietly stopped appearing, and the only reason anyone noticed was customers emailing to ask where their discount code had gone.

That is one of the most expensive failures in ecommerce email, and it happens more than you would think. A broken pop-up does not throw an error. It does not send you an alert. It just silently switches off your single biggest source of new subscribers while everything looks fine from the front end.

Quick answer: If your email sign-ups have quietly dried up, your pop-up has probably broken without telling you. The most common culprit is a time-delay trigger that stops firing after a platform or theme update. The fix is to switch the trigger from a timer to behaviour, so the pop-up shows at a 40% scroll or on exit intent, and to test it properly in an incognito window. Small change, huge difference to your list growth.

How can a pop-up break without you knowing?

A sign-up pop-up, the little form that offers a discount in exchange for an email, is a piece of software sitting between your website theme, your email platform and your shop settings. When any one of those updates, the pop-up can stop firing and nothing on your dashboard will tell you.

This is the part that catches founders out. The pop-up still exists. If you go looking for it, you can often still trigger it manually. But the automatic behaviour, the thing that makes it actually pop up for a real visitor, quietly fails. So you glance at your site, see the form is still there in the settings, and assume everything is working.

Meanwhile your form views crater, your welcome flow gets almost no new entries, and your list growth flatlines. The damage is invisible until you go looking at the right number.

The scariest failures in email are the silent ones, because a broken flow that still looks fine can cost you for months.

What number actually tells you the pop-up has stopped working?

Forget how the pop-up looks. Look at form views over time.

Your email platform tracks how many times the sign-up form has been shown. Pull that number for the last three or four months and put them side by side. A healthy pop-up shows a fairly steady view count month to month, moving up and down with your traffic. A broken one shows a cliff.

When you see 25,000 views collapse to a few hundred while your website traffic held steady, that is not a slow month. That is a mechanical failure. Traffic that size cannot possibly produce that few form views unless the form has stopped appearing.

Watch the welcome flow too. Your welcome flow, the automated sequence that greets new subscribers, is fed directly by sign-ups. If entries into that flow have dropped off a cliff at the same time, you have your confirmation.

Why does switching the trigger fix it?

Most pop-ups fire on a time delay. Show after 8 seconds, that sort of thing. It works until it doesn’t, and a time-based trigger is exactly the kind of thing that quietly stops firing after a theme change or a platform update.

The reliable fix is to trigger on behaviour instead of a clock.

• Scroll depth. Show the pop-up once someone has scrolled 40% down the page. By then they have seen enough to know whether they are interested, and the trigger is tied to a real action rather than a timer that can silently fail.
• Exit intent. On desktop, show it when the cursor moves towards the close button or the back arrow. You catch people at the exact moment they were about to leave.
• A teaser tab. Keep a small “get 10% off” tab on the side so anyone who closed the pop-up can bring it back. Never remove that teaser, because without it there is no way to re-trigger the offer.

Behaviour-based triggers are not just more reliable, they convert better too. A pop-up that appears because someone showed genuine interest beats one that ambushes every visitor the second the page loads.

Want to know if your setup is quietly leaking subscribers? Take the free Klaviyo Scaling Quiz.

Why is your welcome email arriving too late?

While you are in there fixing the pop-up, check one more setting that quietly costs you sales: the delay on your first welcome email.

A lot of accounts have the welcome email set to send after a one-minute delay, sometimes without the owner ever choosing that. One minute sounds harmless. It is not. In that minute the person has clicked away, changed tabs, or forgotten they signed up at all.

Set the first welcome email to send immediately. The moment someone hands over their email is the moment they are most engaged, still on your site, still thinking about your product.

The gap between “immediately” and “one minute” does not feel like much, but it is the difference between catching someone and losing them.

Should you put the discount code straight on the pop-up?

It is tempting. Skip the email step, show the code the second they sign up, and let them apply it at checkout. Plenty of sites do it.

Here is why we usually advise against it for product brands. When the code appears instantly on the pop-up, people learn they can type any fake email, grab the code and move on. That does two bad things. It inflates your list with dead addresses, and it hurts your deliverability, because sending to fake or unengaged addresses damages your sender reputation and pushes your real emails towards the spam folder.

Delivering the code by email instead means the people who actually want it give you a real address. That first email lands, gets opened, gets used, and that early engagement tells the inbox providers you are a sender worth trusting. Your whole list benefits.

If fake sign-ups are never an issue for you and you are genuinely losing customers at that step, it can be worth revisiting. But as a default, keep the code in the email.

Key takeaways

• A pop-up can break silently after a theme or platform update, switching off your list growth with no warning.
• The number that reveals it is form views over time. A cliff, not a dip, means a mechanical failure.
• Switch the trigger from a time delay to behaviour, a 40% scroll or exit intent, and keep a teaser tab.
• Set the first welcome email to send immediately, not after a one-minute delay.
• Keep the discount code in the email rather than on the pop-up, to protect list quality and deliverability.