Why Your Email Sign-Up Pop-Up Stops Working (And How to Catch It Fast)

Your pop-up could be broken right now and you would not know

Picture this. Customers start messaging you asking where their discount code is. A few more say they never got a welcome email. You assume it is user error, because most of the time it is. Then you check the numbers and your stomach drops.

This happened to a brand I work with. Their sign-up form went from 25,000 views in May to just under 400 in July. Not a typo. A pop-up that had been quietly earning subscribers for months had stopped showing, and nobody noticed until customers complained.

Quick Answer: An email sign-up pop-up can stop working with no error message and without you touching a thing. The first sign is usually customers asking for a discount they never received. Check your form views month on month, and if they have fallen off a cliff, switch the pop-up trigger from a time delay to a behaviour trigger like exit intent or a 40% scroll, then test it yourself in an incognito window.

How does a sign-up pop-up just stop working?

A sign-up pop-up (the form that appears on your site offering a discount in exchange for an email) does quiet, important work. It captures the visitor, adds them to your list, and triggers your welcome flow. When it breaks, all three stop at once.

The frustrating part is that nothing flashes red. A platform update, a theme change, a tiny tweak to the form settings, or a trigger that silently fails can all stop the pop-up from displaying. The form still exists in your account. It just is not showing to the people it is meant to show to.

No error message means the only alarm bell is your own numbers, so those numbers are worth watching.

What are the warning signs?

The clearest signal comes from your customers. When people email or DM asking, “where is my 10% off?” or “I signed up but never got anything,” that is not a dim customer. That is a broken pop-up telling you through your inbox.

The second signal is in your reports. Look at your form views or impressions over the last three months. On the brand I mentioned, it went 25,000 in May, 13,000 in June, then under 400 in July. A drop like that is never normal seasonality. It is a fault.

Here is why it matters so much. That first welcome email alone had generated over $8,000 and a 62% open rate. Every day the pop-up sat broken, that money was not being made. A quiet failure is still an expensive one.

How do I fix a pop-up that has stopped showing?

Start with the trigger. A lot of pop-ups are set to appear after a time delay, say eight seconds on the page. Time delays can silently stop firing. The fix that worked here was switching the trigger to behaviour based, so the pop-up shows on exit intent (when the cursor moves to close the tab) or once someone scrolls 40% down the page. Behaviour triggers are more reliable, and they catch people at a more intentional moment.

Next, sort out the frequency and the teaser. Keep a small teaser tab on the side so anyone who closes the pop-up can open it again, and set the main pop-up to reappear after one day rather than five. You want to give people a genuine second chance to grab the offer without hammering them.

Then test it properly. Open your site in an incognito window so it does not recognise you as an existing subscriber. If you need a fresh email to test with, use the plus trick: add a plus sign and some numbers before the @ in your own address (like yourname+99@yourdomain), and it still lands in your inbox but reads as a brand new sign-up. Run through the pop-up, the footer form and the checkout opt-in, and confirm the welcome email actually arrives.

Should the welcome email send immediately or after a delay?

Immediately. Every time.

On that same account, the welcome email was quietly set to send one minute after sign-up. A minute does not sound like much, but the moment someone hands over their email they are still on your site, still interested, still holding their phone. Wait even a minute and you lose that attention. Set the first welcome email to send straight away.

While you are in there, check what actually triggers the welcome flow. It should fire for any sign-up method, the pop-up, the footer form, an embedded form and the checkout opt-in, not just the pop-up. If it only listens for the pop-up, everyone who subscribes another way silently misses your welcome series.

Not sure whether your own pop-up and welcome flow are firing the way they should? A Mini Klaviyo Audit is the fastest way to find out. It is a 15-minute personalised video walkthrough of your account for $69, delivered in three business days, and it flags exactly this kind of quiet leak. Grab one here: inflowmarketing.co/mini-klaviyo-audit

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

It is tempting, because some checkouts reveal the code instantly. I recommend against it for most brands.

When the code shows the second someone types anything in, people learn to enter a fake email to grab it. Now you have fake addresses on your list, your real customers sign up again with their proper email to actually get the code, and your numbers inflate while your deliverability takes a hit. Emailing the code instead means the people who want it open that first email, which lifts engagement and sender reputation, and that helps every future email land in the inbox.

If fake emails and instant codes are genuinely costing you customers down the track, you can revisit it. Start by protecting your list health.

How do I stop this happening again?

Watch two numbers regularly: your form views and your welcome flow sign-ups. If either drops sharply, treat it as a fault to investigate, not a slow week. Test your forms yourself every so often using the incognito and plus-email trick above. And tell whoever manages your email the moment a customer says they did not get their discount, because that one message is often the first sign of a break, days before you would spot it in a report.

None of this is complicated. It just needs someone actually looking, because a broken pop-up will not tell you it is broken.

Key Takeaways

• A sign-up pop-up can stop showing with no error message, taking your list growth and welcome flow down with it.
• The first warning sign is usually customers asking for a discount they never received.
• Check your form views month on month. A cliff drop is a fault, not seasonality.
• Switch the pop-up trigger from a time delay to exit intent or a 40% scroll, and keep a teaser so people can reopen it.
• Send the first welcome email immediately, and make sure the welcome flow fires for every sign-up method, not just the pop-up.
• Do not put the discount code directly on the pop-up. Email it, to protect your list health and deliverability.