Introduction
If you’ve noticed your Klaviyo abandoned cart flows aren’t performing like they used to, you’re not imagining things. Browser privacy restrictions have fundamentally changed how eCommerce tracking works, and most brands are losing visibility on a significant portion of their customers without even realising it. The culprit? Safari’s Intelligent Tracking Prevention (ITP) and similar privacy measures that delete customer data after just seven days of inactivity.
For Klaviyo users, this creates a frustrating reality: your carefully crafted abandonment flows can only send emails to customers your platform can actually identify. When Safari deletes a returning visitor’s cookie data, Klaviyo treats them as a brand new anonymous user. No profile match means no triggered flow, which means no recovery email. Industry data suggests that Klaviyo can miss up to 60-70% of cart abandoners due to these tracking limitations.
Server-side tracking has emerged as the solution to this growing problem, and platforms like Aimerce are helping Shopify brands recover that lost revenue. In this article, we’ll explore why traditional tracking is failing, how server-side solutions work, and why Aimerce’s approach (built by a former Meta engineer with seven years of platform experience) is delivering measurable results for eCommerce brands using Klaviyo.
Key Takeaways
- Safari’s 7-day cookie limit is costing you revenue: When returning visitors aren’t recognised, your Klaviyo abandonment flows simply don’t trigger.
- Server-side tracking bypasses browser restrictions: By capturing and processing data on your server rather than relying on browser cookies, you maintain customer identity across sessions.
- Aimerce was built by a former Meta engineer: Founder Yiqi Wu spent seven years at Meta working on tracking and data systems, bringing genuine platform expertise to the problem.
- Real results within weeks: Brands report 10-40% lifts in Klaviyo flow revenue and significant increases in addressable audience sizes within the first fortnight.
- First-party data is the foundation: Server-side tracking helps you collect, store and activate your own first-party customer data, reducing dependence on third-party cookies.
Table of Contents
- The Tracking Problem: Why Your Klaviyo Flows Are Missing Customers
- Server-Side Tracking: The Solution to Browser Privacy Restrictions
- Platform Spotlight: Aimerce
- How Server-Side Tracking Supercharges Klaviyo Abandoned Cart Flows
The Tracking Problem: Why Your Klaviyo Flows Are Missing Customers
Understanding why your Klaviyo flows are underperforming requires a quick look at how browser tracking has changed. For years, eCommerce brands relied on cookies to recognise returning visitors and tie their behaviour to existing customer profiles. This system worked well enough until privacy concerns prompted major changes from browser vendors.
What Safari’s 7-Day Cookie Limit Means for Your Email Revenue
Apple’s Intelligent Tracking Prevention, first introduced in 2017, has become increasingly restrictive with each update. The current reality is straightforward but problematic: first-party cookies set via JavaScript are deleted after just seven days if the user doesn’t return to your site. For cookies associated with known tracking domains or those using link decoration (think UTM parameters from Facebook or Google), the window shrinks to just 24 hours.
Consider what this means for a typical eCommerce customer journey. Someone discovers your brand through an Instagram ad, browses your products, maybe adds something to their cart, but doesn’t purchase. They’re busy, so they come back eight days later ready to buy. From Safari’s perspective, that returning customer is now a complete stranger. From Klaviyo’s perspective, there’s no profile to match, no abandoned cart event to trigger, and no recovery email to send. The sale that should have been recovered through your carefully optimised flow simply vanishes.
The Hidden Cost of Invisible Abandoners
The scale of this problem is significant. With Safari commanding substantial mobile market share (particularly in Australia where iPhone adoption is high), and with iOS applying similar restrictions across all browsers on Apple devices, a meaningful percentage of your traffic is affected. Firefox has implemented similar protections, and Chrome continues to tighten its privacy controls.
The maths becomes uncomfortable quickly. If roughly 40% of your potential abandonment audience is invisible to Klaviyo, and abandoned cart flows typically drive 5-15% of email revenue, you’re potentially leaving thousands of dollars on the table each month. The customers are there, they’ve shown intent, but your marketing automation simply can’t reach them because your tracking can’t see them.
Server-Side Tracking: The Solution to Browser Privacy Restrictions
Server-side tracking represents a fundamental shift in how customer data is collected and processed. Rather than relying on scripts running in the browser (which are subject to cookie limitations, ad blockers, and privacy restrictions), server-side tracking captures events on your own server infrastructure.
How Server-Side Tracking Works
In a traditional client-side setup, a JavaScript snippet in the browser captures events like page views, add-to-cart actions, and checkout starts. These events are then sent directly from the browser to platforms like Klaviyo, Meta, or Google. The problem is that this entire process depends on browser cookies to identify who’s performing these actions.
Server-side tracking flips this model. When a customer interacts with your store, the event data is first sent to your server (or a dedicated tracking server), which then enriches that data with additional identifying information before forwarding it to your marketing platforms. This approach has several advantages: it’s not blocked by ad blockers, it isn’t subject to the same cookie restrictions, and it allows for more sophisticated identity resolution across sessions and devices.
The technical implementation typically involves what’s called a Conversion API (CAPI) connection. Platforms like Meta, Google, and Klaviyo all support receiving event data via server-to-server connections. The challenge for most eCommerce brands has been that setting up and maintaining this infrastructure requires significant technical resources.
Why First-Party Data Collection Matters
Server-side tracking also enables better first-party data collection, which is increasingly critical as third-party cookies disappear entirely. When you capture customer behaviour on your own server, you’re building a first-party data asset that you control. This data can be used to create persistent customer identities that survive browser restrictions.
The concept is sometimes called “durable identity” or “persistent shopper profiles.” By storing customer identifiers on your server and using sophisticated matching techniques, you can recognise a returning customer even when their browser cookie has expired. This restored identity then triggers all the downstream benefits: your Klaviyo flows fire properly, your Meta ads receive better conversion signals, and your email strategy actually reaches the people it’s designed for.
Platform Spotlight: Aimerce
Several platforms have emerged to help eCommerce brands implement server-side tracking without requiring a dedicated engineering team. Among these, Aimerce has gained particular traction with Shopify merchants, combining technical sophistication with genuine ease of implementation.
Built by a Former Meta Engineer
What sets Aimerce apart is the background of its founder. Yiqi Wu spent seven years as an engineer at Meta (formerly Facebook), working on the very tracking and data systems that power the platform’s advertising infrastructure. She also contributed to projects at Reddit, including their A/B testing platform. This isn’t theoretical knowledge; it’s hands-on experience with how these systems actually work at scale.
As Yiqi has noted, server-side tracking has three core goals: helping ads perform better by feeding algorithms higher quality data, recovering 10-40% more customer profiles for email flows that would otherwise be missed due to cookie deprecation, and extending cookie retention beyond Safari’s strict seven-day limit. Her perspective comes from having built similar systems inside Meta, which gives Aimerce a genuine technical advantage.
Key Features: Durable ID Technology
Aimerce’s core innovation is what they call “Durable ID” technology. This system creates persistent shopper profiles that survive cookie expiration by combining multiple identifying signals: browser fingerprinting (within privacy regulations), email address matching, cross-session behaviour patterns, and server-side data enrichment. When a customer returns after Safari’s seven-day window, Aimerce can often still recognise them and restore their identity to Klaviyo.
The platform integrates directly with Shopify through a native app, requiring minimal technical setup. Most brands can be live within 15-20 minutes. From there, Aimerce automatically captures events server-side and feeds enriched data to connected platforms including Klaviyo, Meta, Google, and TikTok. The system runs alongside (not replacing) your existing tracking, allowing you to directly compare performance.
Real-World Results for Klaviyo Users
The proof is in the performance data. Across their customer base, Aimerce reports consistent patterns: 10-40% lifts in Klaviyo flow revenue, typically visible within the first two weeks. Some specific examples from their case studies include brands seeing 35% incremental revenue added to existing Klaviyo flows, 20-31% increases in addressable audience sizes, and ROI multiples ranging from 7x to 76x on their Aimerce investment.
Customer testimonials consistently highlight two themes: rapid time-to-value and exceptional support. As one merchant put it in their Shopify review: “Aimerce added 35% incremental revenue to my current Klaviyo flows within just 2 weeks. It was easy to set up with their team within just 20 minutes.” Another noted that “Aimerce is paying for itself and helping us collect more revenue from our Klaviyo flows.”
How Server-Side Tracking Supercharges Klaviyo Abandoned Cart Flows
For Klaviyo users specifically, the impact of server-side tracking is most visible in abandonment flows. These automations depend entirely on Klaviyo’s ability to recognise a customer and match their browsing behaviour to an email address. When that recognition fails, the flow simply doesn’t trigger.
Recovering Lost Abandonment Events
The mechanics are straightforward once you understand the problem. Klaviyo’s standard tracking uses client-side JavaScript to capture events like “Added to Cart” and “Started Checkout.” If the customer performing those actions can’t be identified (because their cookie expired or was blocked), the event either doesn’t fire at all or fires without sufficient identifying information to trigger your flow.
Server-side tracking solutions like Aimerce address this by capturing those same events through the server and enriching them with identifying data from their persistent profiles. The enriched event is then sent to Klaviyo with proper customer matching, triggering your abandoned cart flow for customers who would otherwise have been invisible. The same flows you’ve already built and optimised suddenly reach a much larger audience.
The practical impact on your email campaigns is significant. Industry data suggests that stores using server-side tracking enrichment can see 50% or more increases in abandoned cart email sends, with corresponding revenue lifts. One case study from a competing platform showed 2x revenue from abandonment flows after implementing server-side tracking, simply from reaching more eligible recipients.
Extending Your Retargeting Window
Beyond recovering immediately lost events, server-side tracking extends your effective retargeting window. Safari’s seven-day cookie limit is particularly problematic for brands with longer consideration cycles. If your average customer takes two weeks from first visit to purchase, you’re losing half your potential abandoners before they’ve even had time to decide.
Aimerce specifically addresses this with cookie retention extension to one year, bypassing Safari’s restrictions through server-side storage. This means a customer who browses your products, leaves for two weeks, then returns ready to purchase can still be recognised and still receive relevant communications. For high-consideration purchases like furniture, luxury goods, or B2B products, this extended window is essential for effective lifecycle marketing.
The combination of recovering lost events and extending the retargeting window creates a compounding effect. More customers enter your flows, and they remain targetable for longer. The result is substantially more revenue from the same Klaviyo infrastructure you’ve already invested in building.
Bringing It All Together
The shift toward privacy-first browsing isn’t slowing down. Safari’s restrictions will likely become more stringent, Chrome is implementing its own privacy sandbox, and consumer expectations around data protection continue to evolve. Brands that adapt their tracking infrastructure now will maintain a significant advantage over those who wait.
Server-side tracking isn’t just a technical fix; it’s a strategic investment in your marketing’s long-term effectiveness. By building robust first-party data collection and implementing durable identity solutions, you’re future-proofing your ability to reach customers through email, paid advertising, and personalised experiences. The brands that thrive in this new environment will be those who own their customer relationships rather than depending on browser-based tracking that’s increasingly unreliable.
For Klaviyo users specifically, the opportunity is immediate and measurable. Platforms like Aimerce offer low-risk entry points with rapid payback periods. If you’re losing 30-40% of your potential abandonment audience to tracking gaps, recovering even a portion of that represents meaningful revenue. The question isn’t whether server-side tracking matters; it’s how quickly you can implement it.
How The Orchard Agency Can Help
With over 16 years of experience helping brands harness the power of email marketing, The Orchard Agency has seen what works and what doesn’t across every industry and platform. We’ve partnered with Klaviyo as a certified partner and understand the technical nuances that make or break automation performance.
Our team can help you audit your current tracking setup, identify gaps in your customer identification, and implement solutions like Aimerce to recover lost revenue. Beyond the technical implementation, we’ll help you optimise your abandonment flows to maximise the value of your expanded addressable audience. We also provide ongoing database growth strategies that work hand-in-hand with improved tracking.
Whether you’re looking to diagnose why your Klaviyo flows aren’t performing, implement server-side tracking for the first time, or optimise existing automations for better results, we’re here to help. Get in touch to discuss how we can elevate your email marketing strategy.
Frequently Asked Questions
What is server-side tracking and how does it differ from traditional tracking?
Server-side tracking captures customer behaviour data on your server rather than relying on browser-based JavaScript and cookies. This approach bypasses many browser privacy restrictions, isn’t blocked by ad blockers, and allows for more sophisticated customer identification across sessions. Traditional client-side tracking depends on browser cookies which can be deleted, blocked, or restricted by privacy features like Safari’s ITP.
How much revenue am I losing due to Safari’s cookie restrictions?
The impact varies by audience composition, but brands with significant mobile traffic (particularly iOS users) can be missing 30-40% of their potential abandoned cart audience. With Safari applying seven-day cookie limits and iOS enforcing similar restrictions across all browsers on Apple devices, the cumulative effect on Klaviyo flow performance is substantial. Many brands don’t realise the extent of the problem until they implement server-side tracking and see the increase in triggered flows.
Is Aimerce GDPR compliant and privacy-safe?
Yes. Aimerce uses first-party data collection methods that comply with GDPR and other privacy regulations. Their Durable ID technology operates within the bounds of consented data collection and doesn’t rely on third-party cookies or invasive tracking methods. The platform integrates with Shopify’s consent management framework, ensuring data is only collected when customers have given appropriate permissions.
How quickly will I see results after implementing server-side tracking?
Most brands report measurable improvements within the first two weeks. Aimerce specifically highlights that customers typically see 10-40% lifts in Klaviyo flow revenue within this timeframe. The speed of results depends partly on your traffic volume and the proportion of visitors affected by cookie restrictions, but the impact is generally visible quite quickly in your Klaviyo analytics.
Do I need technical expertise to implement Aimerce?
No significant technical expertise is required. Aimerce offers a native Shopify app that can be installed and configured in approximately 15-20 minutes. Their team provides hands-on support during setup, and the platform runs alongside your existing tracking rather than replacing it. This makes it straightforward to implement and evaluate without disrupting your current operations.
Will server-side tracking also improve my Meta and Google Ads performance?
Yes. The same enriched customer data that improves Klaviyo flow triggers also enhances the conversion signals sent to advertising platforms via their Conversion APIs. Brands using Aimerce report improvements in Meta Event Match Quality (EMQ) scores of 20-25%, which helps the algorithms better optimise ad delivery and targeting. Better data quality across all platforms creates compounding performance improvements.
Sources & Further Reading
- Aimerce Official Website
- How to Choose the Right Server-Side Tracking Solution – Aimerce Newsletter
- Aimerce Shopify App Reviews
- Safari ITP: Everything You Need to Know – Stape
- Klaviyo Flows Enricher – Polar Analytics
- How to Create an Abandoned Cart Flow – Klaviyo Help Centre
