Split Your Desktop and Mobile Forms
Most ecommerce stores run a single responsive pop-up form and call it a day. In my books, that is a mistake. When you run a single form across all screen sizes, you cannot accurately analyse how visitors interact with your brand on different devices. Mobile screen space is tight, user behaviour is different, and design constraints are completely separate from desktop.
We build one version exclusively for desktop devices and a separate version exclusively for mobile devices. This allows us to run clean split tests without muddying our conversion data. It also guarantees that tap targets and input fields are properly proportioned on mobile screens.
On step one of both forms, ask for only two things: first name and email address. Some marketers argue you should only ask for an email to minimise friction, but I disagree. Personalising flow subject lines and body copy with a subscriber's first name consistently drives higher engagement and revenue across our accounts. Ensure your copy is tight, your dimensions fit standard viewports, and a short legal disclaimer sits directly beneath the call-to-action button.
Timing and URL Targeting for the Primary Pop-Up
Timing matters just as much as design. Set your primary pop-up form to trigger after an 8-second delay. Showing a pop-up the exact millisecond someone lands on your site creates immediate friction, while waiting 20 seconds means half your traffic has already bounced. Eight seconds hits the sweet spot between capturing interest and respecting the initial browsing experience.
You must also configure your page targeting correctly. Set this primary form to show on all pages, but add a display rule that excludes any URL containing the word product. We do this deliberately because product page visitors require a different engagement strategy.
Finally, ensure the form is suppressed for existing Klaviyo profiles. If someone is already subscribed to your list, bombarding them with a request to join your newsletter is a terrible customer experience.
Capture Zero-Party Data in Step Two
Once a visitor submits their name and email in step one, take them to step two rather than closing the form. Step two is where you capture zero-party data. This is information a customer deliberately shares with you about their preferences, intent, or pain points.
Use this step to ask one critical question that informs your segmentation. Here are a few practical examples:
- Shopping intent: "Are you shopping for yourself or looking for a gift?"
- Product category: "Which range are you most interested in?"
- Skill level or use case: "Are you a beginner, intermediate, or professional?"
Each answer gets stored as a custom profile property inside Klaviyo. You can then use trigger splits in your welcome series flow to deliver hyper-relevant messaging based on what they just told you. A customer buying a gift needs a completely different email sequence than someone shopping for personal use.
Display the Discount Code Immediately
On the final step of the form (the success screen), give the customer their discount code right there on the screen. Include a button that automatically applies the code to their checkout session if your ecommerce platform supports it.
A common school of thought says you should withhold the code and force the customer to check their inbox to retrieve it. Marketers do this to artificially inflate open rates and warm up sender reputation. Here is the thing: your primary job is to generate revenue, not create unnecessary roadblocks for an eager buyer.
Forcing a shopper to leave your website, open their email app, copy a string of text, and come back to the checkout adds friction. Every additional step reduces your purchase conversion rate. Optimise for the customer journey, not the business vanity metric.
The 45-Second Fly-Out Form on Product Pages
What happens to the visitors who close your initial pop-up? Most brands simply lose them forever unless they scroll to the website footer. To fix this, we set up a secondary capture mechanism using fly-out forms on product pages.
Duplicate your desktop and mobile pop-ups, but adjust three specific settings:
- Form type: Change from a central pop-up to a subtle corner fly-out.
- Targeting: Set the form to display only on URLs containing the word product.
- Delay: Increase the delay from 8 seconds to 45 seconds.
If a visitor has been browsing a specific product page for 45 seconds without adding an item to their cart, they are showing clear hesitation. A non-intrusive fly-out sliding into the corner of the screen with a 10% discount gives them the nudge they need to opt in and complete the purchase.
This secondary mechanism consistently delivers results. Across our client accounts, we typically see primary pop-ups converting between 3.8% on mobile and 6.2% on desktop. The secondary 45-second fly-out routinely captures an additional 3% to 4% conversion rate from high-intent shoppers who dismissed the initial form. That represents hundreds of recovered subscribers every month who otherwise would have left empty-handed.
Final Thoughts
A single generic sign-up form leaves a substantial amount of list growth and revenue on the table. By separating desktop from mobile, capturing zero-party data, and deploying secondary fly-outs on product pages, you build a reliable subscriber acquisition engine. It takes less than an hour to set up in Klaviyo, and the compounding return on your list size is immediate.
If you want our team to audit and build your brand's full opt-in ecosystem, explore our sign-up form services to see how we can help you grow your audience faster.
