The Silent Tax of Walled Gardens: Why Digital Advertisers Need a New Strategy

The data tells a compelling story: nearly 70% of digital advertising spend now flows through closed technology environments controlled by a handful of tech giants. These closed ecosystems, commonly referred to as "walled gardens" in the industry, are dominated by Google, Meta, and Amazon. While they offer unparalleled audience reach and sophisticated targeting capabilities, they extract a hidden cost that rarely appears on financial statements but significantly impacts business outcomes.

At their core, these platforms operate like exclusive clubs with strict membership rules. They provide powerful advertising tools, but require brands to surrender control over their marketing intelligence, measurement frameworks, and customer data. What began as platforms designed to help advertisers connect with audiences have evolved into environments where business leaders must accept limited transparency, proprietary algorithms making decisions they cannot fully scrutinize, and fragmented reporting systems that complicate comprehensive performance measurement.

The challenge has only intensified as retailers like Walmart, Target, and even grocery chains have built their own advertising platforms, replicating the same closed-system approach. Marketing leaders now navigate not just a few walled gardens, but a complex landscape of dozens of closed platforms, each with their own rules and metrics.

This article explores the forces that brought us here, dissects the challenges marketers face in this environment, and offers a forward-looking strategy for brands to regain control. Rather than avoiding these powerful platforms, we’ll show how marketers can adopt an "Open Garden" mindset, one that emphasizes cross-platform measurement, intentional planning, and reclaiming ownership of their advertising outcomes.

The walls may be here to stay, but advertisers can still chart their own path to success within them.

From open web to closed ecosystems: How we got here

The digital advertising landscape has undergone a fundamental transformation over the past decade. What began as the open web, full of promise for transparent programmatic advertising, has evolved into a collection of powerful walled gardens that now dominate the industry.

👉What is a walled garden? A walled garden is a closed advertising ecosystem controlled by a platform (e.g., Google, Meta, Amazon) where data, targeting, and measurement are restricted to that platform. Advertisers must rely on proprietary tools and algorithms, limiting transparency and cross-platform insights.

In the early days, the vision was clear: create an open, automated marketplace where advertisers could reach audiences across the entire internet through standardized technology. Programmatic advertising promised efficiency, transparency, and democratized access. Marketers could buy media across thousands of websites through open exchanges, with full visibility into costs, placement, and performance.

But this vision gradually gave way to a different reality. What started as a race to automate media buying transformed into a competition to control the entire media infrastructure. Tech giants recognized that the real power wasn't in building better advertising tools, it was in creating end-to-end ecosystems that could capture user attention, data, and ultimately, advertising dollars.

The numbers tell a compelling story of this shift. According to Statista, in 2022, walled gardens accounted for a staggering 78% of global digital ad revenue, with projections showing this will reach 83% by 2027. This consolidation of power has only accelerated, with research indicating that nearly 70% of all digital ad spend now flows through these closed environments.

Google, Meta, and Amazon constructed comprehensive ecosystems that combine massive user bases, proprietary data, and sophisticated ad delivery systems. These companies leveraged their consumer products to build advertising powerhouses that operate by their own rules:

• Google DV360 for YouTube: YouTube's massive video inventory can only be accessed programmatically through Google's Display & Video 360 platform, forcing advertisers to use Google's tools under Google's terms. The platform offers powerful targeting but limits data export and cross-platform measurement.
• Meta Business Manager: Facebook and Instagram's billions of users can only be reached through Meta's proprietary system, which provides rich targeting capabilities but operates as a black box for attribution, particularly after Apple's privacy changes disrupted its tracking capabilities.
• Amazon DSP: While offering valuable shopping data and closed-loop attribution, Amazon's demand-side platform restricts detailed performance data export, with Skai noting that advertisers struggle to fully extract and analyze campaign insights.
• Apple SKAdNetwork: Apple's privacy framework has fundamentally changed how iOS app performance is measured, creating another walled approach that limits data granularity and cross-platform attribution.

👉What is DSP? A DSP (Demand-Side Platform) is a software platform that allows advertisers to purchase and manage ad inventory across multiple channels (e.g., display, video, mobile) in real-time. It optimizes ad spend by enabling precise targeting and automated bidding.

Google, Meta, and Amazon alone captured 74% of global digital ad spend, with this concentration even higher in regions with strict privacy regulations like Europe. The historical trend is clear: from 2008 to 2020, US walled garden spending jumped from 52% to over 82% of digital advertising, as reported by Skai.

The drivers behind this shift go beyond just business strategy. These platforms leverage unique first-party data relationships with users, creating environments where advertisers must operate within proprietary systems to reach valuable audiences. The proliferation of mobile devices, where apps dominate over browsers, has further cemented this walled approach.

For advertisers, the promise of the open web has given way to a reality where reaching most digital consumers requires navigating multiple closed ecosystems, each with different rules, metrics, and limitations. The path from programmatic promise to platform power illustrates how quickly digital advertising evolved from an open marketplace to a landscape dominated by a few key gatekeepers.

The question now isn't whether to participate in these walled gardens (their scale makes them essential) but how to do so while maintaining strategic control and measurement integrity for your brand.

The problem isn't access; it's alignment

While walled gardens offer unprecedented audience access, the fundamental challenge they present isn't just about getting in; it's about the misalignment between platform objectives and brand goals. These ecosystems weren't designed primarily to serve advertisers; they were built to monetize user attention while protecting platform interests.

This misalignment manifests in how these platforms structure their KPIs, data models, and optimization algorithms. When you advertise within a walled garden, you're operating inside a system optimized first for platform growth and revenue, second for user experience, and only third for advertiser outcomes.

This fragmentation creates fundamental challenges around limited measurement capabilities and journey fragmentation across channels. While platforms excel at providing sophisticated targeting and delivery mechanisms, they systematically restrict the comprehensive data and insights advertisers need to make truly independent assessments of performance.

This creates what we call the "silent tax" of walled gardens: you essentially rent reach without gaining true insight. The real cost isn't just what you pay for the media, it's the strategic value lost when you can't fully understand, verify, or leverage the results of your investments.

Consider these concrete examples of how this misalignment affects marketers:

• Attribution opacity in Meta and TikTok: Both platforms offer limited visibility into how ad spend translates to conversions. Meta's attribution models changed dramatically after Apple's iOS privacy updates, often conflicting with advertisers' first-party measurements. TikTok similarly presents conversion data that can't be independently verified at the user level. This forces brands into guesswork and potentially misaligned messaging strategies.
• Lack of data export from Amazon DSP: While Amazon's advertising platform leverages valuable shopping data, it restricts detailed performance exports. AdPushup's analysis points out that Amazon maintains tight control over information, allowing you to see results but limiting your ability to combine that data with other sources for comprehensive analysis. Skai specifically identifies that extracting granular performance data from Amazon presents significant challenges for advertisers.
• Limited cross-channel tracking in YouTube campaigns: YouTube campaigns, managed through Google's DV360, lack seamless integration with non-Google platforms. This creates blind spots in understanding how video campaigns influence conversions on other channels, forcing advertisers to rely on Google's view of performance rather than a holistic measurement approach.
• "Black Box" algorithms in self-serve platforms: Platforms like Google Ads use increasingly opaque machine learning models to determine ad placements and optimizations. Advertisers have little to no control over these proprietary algorithms, which often prioritize the platform’s own interests. As a result, you’re left making decisions without clear insight into how your campaigns are being executed or why certain outcomes occur.

This pattern extends across all major walled gardens. eMarketer reports a growing distrust of major platforms among advertisers, with many turning to third-party measurement solutions precisely because of these alignment issues. When platform-reported performance consistently looks better than independently measured results, advertisers face a fundamental question of trust.

‍

{{walled-gardens-fig-1}}

‍

The implications go beyond just measurement challenges. When advertisers can't fully understand or control how their campaigns perform across channels, they lose the ability to make strategic decisions about budget allocation, creative optimization, and audience development. Each walled garden presents its performance in the most favorable light, creating a fragmented view that serves platform narratives rather than unified brand objectives.

The real cost of operating in walled gardens is the strategic insight you forfeit when you can't fully understand or control your media investments. This insight gap represents the true challenge of navigating environments that are fundamentally designed to serve platform interests first and advertiser needs second.

Retail media: The newest wall on the block

The explosive growth of retail media networks (RMNs) represents the latest chapter in the walled garden story and, perhaps, the most telling indicator of where digital advertising is headed. What began as a promising new frontier has quickly replicated the same structural challenges we've seen with established tech platforms, only now multiplied across dozens of retailers.

👉What is a retail media network (RMN)? Retail media networks (RMNs) are advertising platforms created by retailers (e.g., Walmart) to monetize their digital properties. These networks provide advertisers with access to first-party data and premium ad placements within the retailer’s ecosystem.

The numbers tell a compelling growth story. eMarketer forecasts U.S. retail media ad spend will reach $41.2 billion in 2024, growing at an impressive 26% year-over-year. By 2028, retail media is projected to account for nearly 20% of total U.S. media spend, up from its current 14.1%. BCG's analysis is even more striking, estimating that the global commerce media market will reach $110 billion by 2026, with profit margins of 70-90% for onsite media, figures that explain why every major retailer is rushing to build their own advertising platform.

But this gold rush has created significant challenges for advertisers. As Digiday reports, marketers now find themselves managing between five and nine different retail media networks, each with its own interface, metrics, and limitations. A survey cited in their research found that 57% of marketers identified this fragmentation as a major challenge, citing "lack of standardization across platforms" and inconsistent data and reporting as key pain points.

What makes this trend particularly concerning is how quickly retail media networks have adopted the walled garden playbook:

• Walmart Connect has built a sophisticated advertising platform that offers valuable first-party shopper data, but only through tightly controlled access points. Advertisers cannot freely export or analyze this data unless they use Walmart's API on Walmart's terms, creating another closed ecosystem where performance validation must happen within Walmart's framework.
• Target Roundel operates as a fully closed ecosystem, with data tightly integrated between in-store purchases and app usage. While this creates powerful targeting capabilities, it also means advertisers must accept Target's measurement methodology, with limited ability to independently verify results or measure cross-channel impact.
• Instacart Ads exemplifies the walled approach to performance data, with ad placements directly tied to search position within their marketplace. The platform offers compelling closed-loop measurement for products purchased through Instacart, but provides minimal post-click insights and limited data interoperability with other marketing channels.

Other rapidly growing networks like Kroger Precision Marketing, Best Buy Ads, and Lowe's One Roof Media have followed similar patterns. MyTotalRetail highlights that 35% of marketers cite the complexity of purchasing ads across these networks as a top barrier, with brands now working with an average of 25 media partners, 22 agencies, and 23 ad tech platforms.

‍

The technical limitations compound these challenges. Many retail media networks don't support third-party tracking pixels, severely restricting independent measurement. Those that do often limit what can be measured, creating incomplete pictures of campaign performance. As Improvado's analysis of top retail media networks notes, the lack of third-party validation forces marketers into fragmented, non-interoperable ecosystems where comparing performance across networks becomes nearly impossible.

Grocery Dive points to another critical limitation: the disconnect between online and offline behavior. Traditional RMNs offer little visibility into in-store behavior, creating blind spots in understanding the full customer journey. This means advertisers must often accept faith-based attribution rather than evidence-based measurement.

What makes this trend particularly concerning is the speed at which it's happening. It took the tech giants a decade to build their walled gardens. Retailers are doing it in just a few years, leveraging the same playbook but with even less transparency from the start.

The déjà vu feeling is unmistakable. Just as marketers have begun developing strategies to navigate the established walled gardens, they now face a proliferation of smaller but equally closed ecosystems. Each promises unique audience access and closed-loop measurement, but each also comes with its own set of rules, limitations, and opacity.

For brands, especially those in CPG and retail categories, this creates an urgent strategic question: how to capitalize on the undeniable reach and targeting benefits of retail media networks while avoiding the fragmentation trap that could undermine cross-channel measurement and strategic control. As these new walls continue to rise, brands need a cohesive approach that preserves their ability to understand the complete customer journey, not just the isolated segments each retailer chooses to reveal.

‍

retail-media-trends-banner

‍

The strategic trade-off: Reach vs. intelligence

When it comes to walled gardens, brands face a fundamental strategic trade-off: access to massive, engaged audiences versus control over their marketing intelligence. This isn't simply a theoretical concern, it's a practical business challenge that affects how marketing budgets are allocated, how success is measured, and ultimately, how brands grow.

The reach advantages of walled gardens are undeniable. For any brand with scale ambitions, these platforms are essentially non-negotiable parts of the media mix. However, this reach comes with significant long-term costs that extend beyond just the media spend:

• Data isolation: When your campaign data lives in siloed platforms, you lose the ability to understand cross-channel effects. These data silos make it difficult to optimize campaigns across platforms, forcing marketers to make decisions with incomplete information.
• Lack of benchmarking: Without consistent measurement across platforms, it becomes nearly impossible to determine relative performance. Is your Meta campaign truly outperforming your Amazon campaign, or are the measurement methodologies simply different? Improvado highlights that walled gardens offer limited data access at higher costs, making true performance comparison challenging.
• Limited strategic control: Perhaps most critically, operating primarily within walled gardens means surrendering control over your marketing intelligence. As noted by Blockthrough, this leads to an incomplete understanding of your audience, with publishers and advertisers increasingly forming alliances specifically to regain this control.

The key insight here isn't that brands should abandon walled gardens: that would be impractical and counterproductive. Instead, the solution lies in a strategic reframing: use walled gardens for their reach, not for your intelligence.

‍

{{walled-gardens-fig-2}}

‍

This distinction leads to a practical framework that sophisticated marketers are increasingly adopting:

1. Use walled gardens for reach, not intelligence

Approach platforms like Google, Meta, Amazon, and retail media networks as powerful distribution channels, but not as your primary sources of marketing truth. Recognize that each platform will present its performance in the most favorable light, and design your measurement approach accordingly.

In practice, this means maintaining a healthy skepticism toward platform-reported metrics while still leveraging their powerful targeting and delivery capabilities. eMarketer reports that forward-thinking advertisers are increasingly turning to third-party measurement solutions precisely because of growing distrust in platform-reported results.

2. Centralize measurement via neutral tools

Build your measurement infrastructure on neutral ground, outside the influence of any single platform:

• Unified ID solutions: These identity frameworks help connect user journeys across platforms while respecting privacy concerns. They provide more consistent cross-channel measurement than relying on platform-specific identifiers.
• Clean rooms: These privacy-preserving environments allow advertisers to match and analyze data across platforms without exposing personal information. They're increasingly essential for connecting walled garden data with first-party customer information.
• Data warehousing: Centralized data repositories that bring together platform data, CRM information, and sales results create a single source of truth independent from any platform's reporting.

These approaches offer flexibility and visibility beyond what walled gardens provide, supporting a more balanced measurement strategy that serves brand objectives rather than platform interests.

3. Leverage cross-platform intelligence engines

Employ technologies that can plan, optimize and unify insights across all your marketing channels:

• Cross-platform planning tools: These allow budget allocation based on unified business outcomes rather than platform-specific metrics.
• Neutral optimization engines: Technologies like Elevate that optimize across platforms based on true business impact, not just platform-reported performance.
• Unified analytics dashboards: Tools that bring together performance data from all channels to provide a complete view of the customer journey.

The long-term benefits of this approach extend beyond just better measurement. By centralizing your marketing intelligence outside walled gardens, you build institutional knowledge that persists regardless of platform changes. You also gain strategic flexibility, allowing you to shift investments quickly as performance or market conditions change. 

The brands that thrive in this fragmented landscape won't be those that master each individual walled garden. They'll be the ones that build systems to understand performance holistically, making informed decisions about where and how to invest across all channels based on true business outcomes.

Building for what comes next: Open Garden thinking

As discussed throughout this piece, the digital advertising ecosystem creates inherent challenges for brands seeking strategic coherence. However, a solution exists despite the dominance of walled gardens. Forward-thinking marketers are now adopting a more empowered position through what we call the Open Garden approach.

Open Garden isn't simply a technology stack or platform; it's a strategic mindset that puts brands back in control of their digital destiny. At its core, this approach recognizes that while walled gardens are essential channels, they shouldn't dictate how brands measure success, allocate resources, or understand their audiences.

👉 How does Open Garden differ from Open Internet? The Open Garden is a structured framework that provides cross-platform advertising transparency and control, combining elements of both walled gardens and the open internet. In contrast, the Open Internet broadly refers to the unrestricted, non-proprietary portion of the web where advertisers can access inventory and data freely. Open Garden enhances the open internet by integrating AI-powered tools, unified insights, and DSP-agnostic execution for optimized ad performance.

The four pillars of Open Garden thinking

1. DSP-agnostic operations

Open Garden thinking starts with platform neutrality. It means building measurement and optimization frameworks that work across all platforms without being beholden to any single ecosystem's metrics or methodologies.

In practice, this means having the flexibility to shift investments based on true performance, not platform convenience. As the data shows, when advertisers can freely compare results across channels, they consistently make different allocation decisions than when working within platform-specific reporting. This is particularly crucial given that Meta and Google generated $131.95 billion and $237.86 billion in advertising revenue, respectively, in 2023, surpassing all other ad tech companies combined, creating an environment where platform-specific optimization can limit broader strategic effectiveness.

👉 What does DSP-agnostic mean? DSP-agnostic means independent of any specific DSP, allowing advertisers to use multiple DSPs without bias or restriction. This ensures flexibility, transparency, and the ability to select the best-performing platforms for their campaigns.

2. Outcome-driven measurement

Where walled gardens optimize for engagement metrics like clicks and impressions, Open Garden approaches prioritize actual business outcomes. This fundamental shift aligns marketing activities with the metrics that drive business growth.

The challenge is that most AI-driven technologies in the marketplace are still optimizing for vanity metrics rather than business impact. When marketing technology prioritizes media metrics over business results, it creates a fundamental misalignment with brand objectives. 

Leading brands have already recognized this: P&G's "smart audience" campaign using first-party data and cross-platform targeting reduced ad spend by 10% while increasing sales by 20%, demonstrating the power of outcome-driven measurement over platform metrics.

3. Transparency at every level

Open Garden demands transparency in data, algorithms, and performance. This means having visibility not just into what happens, but why it happens, especially when AI systems are making decisions.

The industry's status quo features what our team calls "black box" optimization, where marketers lack control and understanding of AI-driven decisions. True transparency isn't just about seeing the results; it's about understanding the logic behind the algorithms determining where your media dollars go, a requirement increasingly aligned with regulatory trends demanding transparent AI models across industries.

4. Business alignment, not platform metrics

Perhaps most importantly, Open Garden thinking aligns marketing operations with overall business goals rather than platform-specific metrics. This means developing custom KPIs that reflect true business impact and optimizing toward those outcomes across all platforms. This inherent conflict of interest between DSPs and advertisers means that letting platforms dictate measurement frameworks inevitably leads to suboptimal business outcomes. This is particularly problematic when walled gardens' reach is limited to platform users, potentially missing 30-50% of consumers, according to digital commerce analysts.

‍

Implementing the Open Garden approach

Open Garden doesn't mean avoiding walled gardens (that would be impractical and counterproductive). Instead, it means approaching these powerful platforms with your own rules, measurements, and benchmarks.

This requires building infrastructure that sits above the walled gardens, providing a unified view of performance and enabling cross-platform optimization based on true business outcomes. It means maintaining control of your first-party data and leveraging it consistently across platforms rather than fragmenting it into platform-specific segments. Mondelēz International demonstrated this approach by achieving a 16% sales lift through merging social platform and retail network data via integrated data solutions, enabling better targeting and measurement across channels.

How advanced technologies enable Open Garden strategies

New technologies are emerging specifically designed to support Open Garden approaches. These systems connect disparate platforms, provide unified measurement, and enable optimization based on custom business outcomes rather than platform metrics.

For instance, Elevate's AI Intelligence Engine exemplifies this approach by addressing the fundamental challenges of fragmentation, opacity, and bias in the current martech landscape. The system connects to 15+ DSPs while remaining platform-neutral, ensuring that optimizations serve advertiser goals rather than platform interests. This aligns with industry trends toward interoperable data solutions, which simplify insights management across walled gardens and reduce the complexity of platform-specific approaches.

What makes technologies like Elevate particularly valuable in enabling Open Garden strategies is their combination of AI-powered intelligence with human oversight. This ensures that technological sophistication doesn't come at the expense of strategic control.

The technical capabilities required for true Open Garden operation are substantial. Elevate's system, for example, processes 6+ years of historical & real-time data from DSPs and measurement tools across 10,000+ campaigns, creating AI models that are fine-tuned daily using live campaign data. This level of sophistication is necessary to counter the massive technological advantages that walled gardens have built.

Most importantly, these Open Garden technologies provide what walled gardens systematically deny: transparency into how decisions are made. Elevate's approach ensures no black boxes, just data-driven AI where clients can see and validate every decision, a stark contrast to the typical black-box optimization found in platform-specific tools.

‍

explore-elevate-banner

‍

The business impact of Open Garden thinking

Brands that adopt Open Garden approaches see tangible business results. Our case studies show specific outcomes for advertisers implementing Elevate, like an 11% increase in audience reach, a 16% reduction in cost per acquisition, and a 23% improvement in media efficiency, precisely because they're optimizing toward business outcomes rather than platform metrics. And these results don't come from avoiding walled gardens but from engaging with them strategically. 

Conclusion: The walls aren't coming down, but you can still build your own rules

The reality we face as marketers is both challenging and clarifying: the walls aren't coming down. The digital media ecosystem isn't reverting to open pipes and raw data feeds. Fragmentation isn't a temporary condition; it's the new foundation of our industry. The walls are here to stay, but your approach to them doesn't have to be reactive or surrendering.

What we've learned from working with hundreds of brands navigating this landscape is that success doesn't come from mastering each walled garden's specific rules and metrics. It comes from building systems that transcend them, frameworks that maintain strategic control regardless of how platforms evolve or how many new walls appear.

The marketers who thrive in this environment won't be the ones who become experts in every platform's nuances. They'll be the ones who design their own rulebooks and who build measurement frameworks that answer their questions, not the platforms'. They'll be the ones who leverage walled gardens for their reach and targeting capabilities while maintaining independent systems for intelligence and decision-making.

If walled gardens are the new normal, then owning your outcomes must become your new default. This means investing in neutral measurement infrastructures, building cross-platform optimization capabilities, and maintaining the strategic flexibility to shift investments based on true performance, not platform convenience.

The good news is that the technology to enable this approach exists today. Elevate delivers precisely this capability, a platform-neutral system that connects across the fragmented landscape while maintaining your strategic independence. 

The walls define the landscape, but they don't have to define your approach to it. By building your own rules, your own measurements, and your own benchmarks, you can navigate this complex ecosystem on your terms.

Let’s keep the conversation going, feel free to reach out: 

📩 Mary Gabrielyan

📧 mary.gabrielyan@aidigital.com

🔗 LinkedIn