Are your abandonment flows really capturing every customer?

For most fashion brands, flows are the quiet backbone of retention: welcome series, browse abandonment, cart recovery, back-in-stock, post-purchase. When they're built well, they run in the background and convert without extra ad spend. The dashboards look healthy, the logic is sound, and revenue keeps coming in.

What most brands don't see is how many customers never made it into the flow at all.

The challenge isn't the flow itself. It's that standard tracking never registered the customer who should have triggered it.

At Not selling liquid, we work with fashion and lifestyle merchants across Benelux and Europe. As a Shopify Premier Partner, Klaviyo Gold Master and Triple Whale partner, we increasingly see the same gap across accounts: brands with strong-performing flows that are still missing a meaningful share of the customers those flows were built for.

The real gap: why cookie-based tracking misses customers

Klaviyo relies on a cookie placed in the browser to recognise a customer and fire the right automation. It works well in theory. In practice, cookies are fragile: they get cleared, blocked by ad blockers or privacy-focused browsers, or they simply expire before the customer comes back.

None of this shows up as a problem anywhere in your reporting. The flow is live, the segmentation is correct, the copy is on-brand. What's missing is invisible: the customer who added to bag and left, and never received the email, because the platform never saw the event that should have triggered it.

Why fashion shopping behaviour makes this worse

Shopping is rarely a single-session decision, which makes this gap larger than in most other categories.

• Someone spots a piece on Instagram on their phone during a commute, taps through, and leaves without adding to bag.
• A customer adds a coat to their bag, then leaves to check the size guide or a sizing thread, and comes back two days later on a different device.
• A customer waits for a restock, checking in from mobile, tablet and desktop across several sessions before the size they want is back.

Each of those re-entries is another chance for the cookie trail to break, and for the flow that was meant to catch them to never fire at all.

Closing the gap without changing the flow

The fix isn't a new set of automations. It's strengthening the data feeding the ones already built.

Triple Whale's Sonar Send takes this approach. Instead of relying solely on the browser cookie, it combines an on-site pixel with server-side signals, such as checkout and order events, to resolve identity independently of the cookie. When a customer eventually converts, whichever device or session that happens on, their earlier activity is linked back to a single profile rather than left scattered across several anonymous ones.

• In Klaviyo, this runs as a parallel structure: existing abandonment flows are cloned, with the Sonar-triggered version catching customers the standard tracking missed. If Klaviyo sees the event, the customer moves through the flow as normal. If it doesn't, the enriched version catches them instead.

Nothing about the strategy, segmentation or creative changes. What changes is how many of the right customers actually reach it.

Why it's worth checking, not just reading about

Brands that have layered this onto an already healthy flow set have reported meaningful incremental revenue, not from a new channel, but from closing gaps in the one already in place. For fashion specifically, where cross-device browsing before a purchase is closer to the norm than the exception, that gap tends to be larger than most teams expect.

Final thought

A flow that looks like it's performing well can still be missing a large share of the customers it was built for. The strategy isn't the problem. The data reaching it is.

At Not selling liquid, we build, manage and grow fashion brands in the digital space. From Klaviyo retention to Shopify Plus builds and Triple Whale reporting, we help fashion and lifestyle merchants make sure their flows are reaching everyone they were designed for.

If your flows have been performing steadily and you haven't checked what might be missing them entirely, we're happy to take a look together. In case you're not using Triple Whale yet, discover more here.