Most ecommerce brands treat their sign-up form as an afterthought. They drop a single pop-up on their homepage, ask for an email and a phone number on step one, and wonder why their list growth stalls or their bounce rate climbs.
When we manage email and SMS for high-volume Shopify brands doing millions in monthly revenue, our capture architecture looks completely different. For one client doing roughly $3 million a month, we run eight distinct forms simultaneously. Every form has a dedicated job, a specific trigger, and clean segmentation behind it.
Separate Desktop and Mobile Forms for Accurate Data
The first rule we enforce is separating desktop and mobile forms into distinct assets inside Klaviyo. We never run a single responsive form across both devices if we want clean test data.
People interact with mobile devices using their thumbs, while desktop users navigate with a cursor. The layout, button sizing, and screen real estate requirements are fundamentally different. More importantly, when you run an A/B test on a combined form, the device split muddies your numbers and hides what is actually working.
Our baseline desktop and mobile pop-up displays after an 8-second delay on general store pages. We exclude existing profiles, cart pages, checkout pages, and order confirmation URLs. That gives new visitors enough time to view the site before being presented with an incentive.
Zero-Party Data Collection and Frictionless Discounts
On our initial pop-up, we offer a 10% discount. In my books, percentage discounts work better than fixed dollar amounts because they naturally encourage a higher average order value. The more a customer spends, the more they save.
Step one collects the email address. Step two immediately asks for zero-party data by asking what category they are shopping for (such as engagement rings, wedding bands, or necklaces). We map each selection to a custom profile property tag. That allows us to split our automated welcome series and deliver tailored product recommendations right out of the gate.
On the success step, we do something most stores miss. We display the discount code directly and embed it into the call-to-action button URL so it auto-applies at checkout. Forcing a subscriber to leave your site and check their inbox just to find a coupon code destroys your conversion rate. Keep them on the site while purchase intent is high.
Capturing Missed Leads on High-Intent URLs
Visitors who close the initial pop-up and navigate deeper into your catalogue are demonstrating stronger buying intent. If you only show one pop-up per session, you lose the opportunity to convert them once they reach high-value pages.
We build a secondary set of forms (again, split between desktop and mobile) configured as subtle flyouts. These flyouts only trigger on URLs containing keywords like product, cart, or checkout, and they appear after a 45-second delay.
This is not aggressive spam. It is a well-timed second chance for an engaged shopper who rejected the generic pop-up earlier. In a recent 30-day window, this secondary flyout captured roughly 2,300 subscribers who had completely bypassed the first form. That is serious revenue that most stores leave on the table.
Why Asking for SMS on the First Pop-Up Is a Mistake
Almost every agency tells you to capture email on step one and phone numbers on step two of your primary pop-up. That is a mistake.
When you ask for SMS immediately after email on your main form, between 25% and 45% of users drop off and close the modal without reaching the success step. That means nearly half of your new subscribers never see the auto-applied discount button on your site. They end up bouncing to their email inbox to find the code, which tanks your on-site conversion rate.
We protect the purchase path first. We keep the primary form strictly focused on email, zero-party data collection, and instant discount delivery.
The Non-Buyer Reminder and Dedicated SMS Capture
To capture phone numbers and convert non-buyers, we deploy two specialised form sets targeted at specific segments:
- The Non-Buyer Reminder Flyout: Targets a Klaviyo segment of people who have subscribed to email but have not yet placed an order. After 20 seconds on site, a small flyout reminds them of their unused 10% discount code. It does not ask for an opt-in, it simply removes friction to drive the first sale.
- The Email-Only Subscriber SMS Form: Targets users who are active email subscribers but have no phone number on file. This form triggers after 30 seconds on site with a 14-day reappearance limit, inviting them to receive text updates without interrupting first-time site visitors.
By segmenting our forms based on user status and intent, we capture SMS consent from qualified subscribers without sacrificing the conversion rates of brand-new traffic.
Final Thoughts
High-converting email and SMS systems are built on relevance and timing, not a single intrusive pop-up. Splitting your forms by device, gathering zero-party data, targeting high-intent URLs, and separating SMS acquisition will immediately lift both your list growth and your store revenue.
If you want our team to audit your current capture setup and build a high-converting acquisition strategy for your store, explore our Sign-Up Form Optimisation Services.
