If you’re running a Shopify store and your entire retargeting strategy depends on third-party cookies, I have some bad news. You’re already operating on borrowed time.
Last year, Apple blocked third-party cookies in Safari. Firefox did the same. And while Google’s been playing ping-pong with their deprecation timeline (announcing it, delaying it, then quietly pivoting to alternatives), the reality hasn’t changed: third-party cookies are dead, and most Shopify merchants haven’t noticed yet.
Here’s what actually triggered this wake-up call for me: A client running $2M annually through paid ads came to me in September saying their retargeting conversions had tanked. We dug into the numbers. Their ROAS on cookie-based retargeting had dropped from 3.2x to 1.8x in three months.
They were still spending the same budget, reaching fewer people, with worse results. They hadn’t changed anything on their end.
That’s the environment we’re in now.
What Actually Happened to Your Audience
Let me be specific about what broke. When you used to run a retargeting campaign, you’d follow a customer across the web. They’d browse your Shopify store, leave, and then see your ads on Facebook, Instagram, Google Display Network, news sites, basically everywhere. That worked because third-party cookies tracked their movement.
Today? Try to retarget the same customer:
On Safari: She’ll see your ads nowhere because Safari blocked third-party cookies in 2020. Apple users make up ~30% of web traffic in most markets. You literally can’t reach them through traditional retargeting.
On Firefox: Same situation. Another 5-10% of your audience you can’t reach.
On Chrome: This is where it gets messy. Google said they’d phase out third-party cookies. They delayed it multiple times. Then, in September 2024, they announced they’re actually not killing third-party cookies completely. Instead, they’re giving users controls through Privacy Sandbox.
But here’s the catch—they’re actively discouraging extensions and tools that block cookies, which is basically admitting the current system is broken.
The result? Around 70% of your potential customers either can’t be retargeted, are blocking cookies outright, or are inconsistently visible across the web. Your old playbook doesn’t work anymore.
Rising Customer Acquisition Costs: The Impact of Third-Party Cookie Deprecation
The Math Gets Ugly Fast
Customer acquisition costs were already climbing. My clients were telling me in 2023 that CAC was trending around $29-32 per customer, depending on industry. Now? We’re seeing jumps to $36-45 in competitive niches. That’s a 40%+ increase in 18 months.
Why? Because you’re no longer bidding to retarget interested people. You’re bidding to reach everyone and hoping some convert. Your targeting precision has gone from “people who visited our product page” to “people in our demographic who maybe like similar stuff.” That’s a massive efficiency loss.
For a store doing 100 conversions daily at $40 CAC, that’s $4,000 you’re spending every single day. A 40% increase? That’s $1,600 extra daily just to maintain the same conversion volume. That’s $48,000 more per month. For smaller stores operating on thin margins, it’s existential.
Average Ecommerce Conversion Rates by Industry (2025)
The Part That Keeps Me Awake at Night
Here’s what worries me more than rising CAC: You can’t even measure what’s working anymore.
Your analytics are becoming guesses. Without reliable cross-device, cross-browser tracking, you genuinely don’t know if that sale came from your email yesterday, an organic search three days ago, or paid ads last week. Your attribution model is lying to you.
I worked with a Shopify store running 40% of their budget into Google Search Ads. Their analytics said Search was responsible for about 30% of revenue. But when we actually traced customer journeys through our CRM (email addresses, purchase history), we discovered Search was only driving maybe 15% of attributed sales. The other 15% they’d credited to Search? Those were repeat customers who’d been nurtured by email over weeks. But they happened to search for the brand right before buying, so Google grabbed the credit.
That client’s been over-investing in Search by hundreds of thousands annually. Analytics didn’t lie intentionally—it was just the best guess the system could make with cookies.
Now imagine that exact problem across all your channels, getting worse. That’s where you’re headed.
Addressable Audience Distribution in a Cookieless World
Stop Waiting for Privacy Sandbox to Save You
Google keeps talking about Privacy Sandbox as the solution. I keep hearing merchants say “okay, so we’ll just use Topics API instead of cookies.”
Nope. That’s not how this works.
First, Privacy Sandbox isn’t live at scale yet. Topics API exists in Chrome but adoption from advertisers is slow because—and I’ll be blunt—it doesn’t work as well as cookies. Criteo tested it. Google’s own privacy API was 5x less effective at driving conversions than third-party cookies. That’s not a viable replacement. That’s a fallback plan.[4]
Second, and more importantly: Privacy Sandbox still requires giving Google visibility into your customer behavior. You’re not gaining independence. You’re just trading one surveillance system for another one run by Google. Your data still flows through their infrastructure. You still have no direct relationship with your audience.
That’s not a solution. That’s a slightly shinier version of the same problem.
What Actually Works: First-Party Data
Here’s the thing nobody wants to hear because it’s less exciting than perfect pixel tracking: the merchants winning right now are boring.
They’re building email lists. SMS subscriber lists. Loyalty programs. Post-purchase surveys. Wishlists. Referral lists. Basically, they’re collecting information directly from their customers instead of inferring behavior through tracking pixels.
This works because:
It doesn’t break. A customer who signs up for your email list stays on your email list until they unsubscribe. A browser cookie gets deleted, blocked, or expires. Guess which one’s more reliable?
You own it. That email list isn’t living on Google’s servers or Facebook’s infrastructure. It’s yours. You control how you use it. Nobody’s algorithm can take it away.
Customers expect communication. When someone opts into your SMS list, they’re literally saying “text me.” Engagement rates reflect that—email open rates sit around 25-30%, SMS open rates are 95%+. People who willingly subscribed act differently than people you’re chasing with retargeting pixels.
Shopify First-Party Data Collection Methods Comparison
Let me give you a real example: I was consulting with a skincare brand doing $800K annually through Shopify. They were spending about $12K monthly on retargeting. Results were mediocre. We shifted strategy.
Within three weeks, we launched a “Free Skincare Quiz” lead-gen campaign on Meta. The quiz asked five questions: skin type, main concern, budget, sensitivity, and ingredient preferences. We drove 2,100 people to the quiz at about $2.50 per quiz completion. Cost? $5,250.
We added those 2,100 to their email list and segmented them based on quiz responses. Then we sent each segment a personalized product recommendation email. First email went out on day 3.
Result: 312 of those 2,100 people bought within 7 days. That’s a 14.8% conversion rate on a cold audience. The average order value was $68. Revenue from that campaign: $21,216.
All from asking people what they actually wanted instead of chasing them with retargeting pixels.
They didn’t rebuild their entire strategy overnight. But that test convinced them to shift the budget from paid retargeting (which was becoming less effective) into list-building ads (which fed email sequences that worked).
Your Actual Roadmap (Realistic Version)
Stop waiting for a magic solution. Here’s what works in the real world:
Month 1: Audit what you’re actually using
Look at your ad accounts. Your Google Analytics. Your email tool. Write down: “What third-party cookies are doing heavy lifting right now?” For most stores, it’s Facebook pixel retargeting and Google Analytics cross-domain tracking. That’s it. Most of your other “advanced tracking” isn’t doing much anyway.
Month 2: Build multiple first-party channels simultaneously
Don’t just add an email pop-up. That’s amateur hour. Create three different entry points:
- Post-purchase survey (ask what they loved, what they’d change, when they might buy again) using something like Fairing or Glow
- Lead-gen campaign (quiz, checklist, discount—something valuable) driving to your email list
- SMS opt-in at checkout with an immediate incentive (5% off next order, free shipping on replenishment, etc.)
Don’t overthink this. Just get data flowing in. A client of mine added SMS opt-in at checkout, and 34% of customers opted in. That’s 34% of their customer base now getting direct text access that is not affected by any cookie deprecation.
Month 3: Get your analytics honest
Set up Google Analytics 4 properly with Shopify integration. GA4 works without third-party cookies. It’s not perfect, but it’s way more honest about what’s actually happening in your store. Also, enable Shopify’s native reporting. Yes, it’s basic, but it’s accurate.
Set up email tracking so you can see revenue directly from email sends. This is critical—you need to know that “Email Campaign A” directly generated $4,200 in sales on Tuesday. That’s the metric that matters.
Month 4+: Ruthlessly expand what’s working
If your email list is growing at 2% monthly, you’re behind. Aim for 10-15% monthly growth by running consistent list-building campaigns. SMS should start generating 15-20% of email revenue within 60 days of launch if you’re segmenting properly.
6-Stage Implementation Roadmap: Transitioning Shopify Stores to First-Party Data
Stop Thinking Like an Ad Buyer, Start Thinking Like a Retailer
Here’s my honest take: the merchants who built their business on perfect pixel tracking were always playing a rigged game. They were good at gaming the system, not at building relationships.
The ones adapting fastest now are the ones who never depended on it as heavily. They always had strong email programs. They always asked customers questions on surveys. They always tracked customer lifetime value instead of obsessing over single-purchase ROAS.
I worked with a store that had 40,000 email subscribers and was worried about this transition. You know what happened? Nothing. They didn’t even notice cookie deprecation because their marketing worked through owned channels. Their acquisition cost barely moved.
Meanwhile, a competitor at half their revenue size was burning $15K monthly on retargeting with declining results. Same industry, same audience, vastly different outcomes based on strategy choices made 2+ years earlier.
The good news: You can still fix this. You can build a legitimate first-party data operation. It’s not fast or glamorous, but it works.
The bad news: Every month you wait, you’re hemorrhaging efficiency, and CAC is going up. The math doesn’t get better by next quarter. It gets worse.
What You Should Actually Do This Week
- Email your best customers today. Ask them: How did you hear about us? What made you choose us over competitors? When are you most likely to buy again? Their answers will tell you what channels actually matter.
- Look at your analytics. Find your highest-converting traffic source. Then ask yourself: “Am I measuring this accurately?” If it depends on third-party cookies, the answer is probably no.
- Build an SMS opt-in. If you’re not collecting phone numbers at checkout, you’re leaving revenue on the table. This is quick. Shopify makes it easy.
- Set a goal. Commit to growing your email list by 10% this month through paid campaigns. Calculate what that costs per subscriber. Compare it to your CAC. If it’s lower (spoiler: it usually is), you’ve found your new primary channel.
That’s not theory. That’s what’s actually working in stores right now.
Key Takeaways
The third-party cookie is officially obsolete. While Google reversed the timeline for full deprecation, Safari and Firefox have already blocked third-party cookies, and user consent rates sit at only 28%. This means your traditional retargeting reach has collapsed to approximately 30% of its former scope.
Customer acquisition costs are accelerating upward. The combination of cookie restrictions and increased competition for limited addressable audiences is driving CAC up by 40-60% in competitive sectors. For the average Shopify store, acquisition efficiency is becoming harder, not easier.
First-party data collection is no longer optional. Email lists, SMS opt-ins, loyalty programs, surveys, and quizzes now form the foundation of any serious e-commerce strategy. The skincare brand case study showed 14.8% conversion on cold email subscribers segmented by quiz responses.
Compliance is now business-critical. GDPR, CCPA, and similar regulations aren’t enforcement theater anymore. Building consent management and privacy-compliant analytics directly into your store prevents legal risk and builds customer trust.
Email and SMS are your most reliable acquisition channels. Unlike paid social and search (which depend on accurate tracking and third-party data), email and SMS work entirely through first-party owned channels. They’re increasingly becoming the only measurable acquisition mechanisms available to most stores.
Ready to Bring Your Project to Life? Hire a Skilled Software Developer and Watch Your Ideas Flourish!
Pooja Upadhyay
Director Of People Operations & Client Relations
Sources
Google’s Privacy Sandbox: The Winding Road To A Cookie-Less Future – Kevel
https://www.kevel.com/blog/googles-privacy-sandbox-the-winding-road-to-a-cookie-less-future
The Average CAC in Ecommerce (2025) – Loyalty Lion
https://loyaltylion.com/blog/blog-average-cac-ecommerce
Google’s Privacy Sandbox Testing Results – Criteo Research
https://www.kevel.com/blog/googles-privacy-sandbox-the-winding-road-to-a-cookie-less-future
Internet Cookie Statistics: Key Trends and Insights – Cookieyes
https://www.cookieyes.com/blog/internet-cookie-statistics/
How to Collect First Party Data – Shopify Enterprise
https://www.shopify.com/enterprise/blog/holiday-season-customer-data
SMS Marketing Statistics and Best Practices – Adoric
https://adoric.com/blog/sms-marketing-shopify/
