Marketplace and Two-Sided Platforms: What Sellers and Resellers Need to Know About Marketing, Data, and Control

Marketing attribution is the process of identifying which touchpoints contributed to a sale. When those touchpoints occur on a platform you don't own, attribution becomes harder. When the sale itself occurs on that platform, the data gap is structural and requires deliberate infrastructure to bridge. As we covered in our piece on attribution when you don't control the final sale, the measurement challenge in indirect selling models is not a technology problem. It is a visibility problem, and marketplaces represent its most prevalent form.

Two-sided platforms and marketplaces are now the primary discovery and purchase environment for a significant share of consumer and business commerce. Amazon accounts for roughly 40% of US e-commerce. The Apple App Store and Google Play control mobile software distribution for billions of devices. Platforms like Etsy, Faire, Thumbtack, Houzz, Zillow, and Alibaba have become the dominant discovery layer in their respective categories. For sellers and resellers operating in these environments, the marketplace is not a supplement to their marketing program. It is the environment in which the majority of their customers first encounter them.

Understanding what marketplaces control, what they don't, and how to build a marketing and measurement program that accounts for both is foundational for any seller operating at meaningful scale.

What Is a Two-Sided Platform and How Does It Differ from a Traditional Channel?

A two-sided platform connects two distinct groups whose interaction creates value: buyers and sellers, riders and drivers, hosts and guests, developers and users. The platform earns by facilitating those interactions, typically through transaction fees, subscription charges, listing fees, or advertising revenue. The defining characteristic of a two-sided platform is that both sides need to be present for the platform to work, which means the platform has structural incentives to manage the experience of both groups simultaneously.

For sellers and resellers, this structural characteristic has a specific implication: the platform's interests and yours are partly aligned and partly opposed. The alignment exists because the platform needs sellers to create supply, and it needs that supply to be high quality enough to attract buyers. The opposition exists because the platform has its own economic interests in how transactions are structured, what data is captured, and who controls the customer relationship after the sale.

A traditional distribution channel, by contrast, has simpler dynamics. A retailer buys product from a reseller, marks it up, and sells it to a consumer. The reseller has a defined margin, a defined relationship with the retailer, and a relatively predictable commercial structure. A marketplace operates differently: the seller lists directly, the platform controls discovery and ranking, the transaction happens on the platform's infrastructure, and the customer data generated by that transaction largely belongs to the platform.

The practical consequence is that selling through a marketplace is not equivalent to selling through a traditional channel, even when the financial outcome is similar. The control dynamics, the data ownership, and the dependency relationships are structurally different and require a different strategic and marketing response.

What Do Marketplaces Control That Sellers Don't?

Understanding what a marketplace controls is the starting point for building a realistic marketing strategy within one. The list is longer than most sellers initially appreciate.

Discovery and ranking is the most consequential area of platform control. On Amazon, product discovery is governed by the A9 algorithm, which factors in conversion rate, sales velocity, review volume and recency, advertising activity, listing completeness, and pricing competitiveness, among other signals. A seller's visibility to potential buyers is a function of how the algorithm assesses these signals, not of any direct action the seller takes in a traditional marketing sense. A competitor who improves their listing, accumulates more reviews, or increases their advertising spend can displace a seller's ranking without the seller doing anything wrong. The marketplace controls the discovery layer completely, and sellers operate within the rules of that system.

Pricing dynamics on many marketplaces create pressure that sellers on owned channels do not face in the same form. Amazon's algorithms detect pricing that is higher than comparable listings elsewhere and can suppress a product's Buy Box eligibility as a result. This creates a dynamic where pricing decisions made on owned channels have consequences for marketplace visibility, and vice versa. Managing pricing coherence across owned and marketplace channels is an operational challenge that does not exist for sellers operating exclusively on their own storefront.

Review and reputation systems on marketplaces are controlled by the platform. A seller cannot remove a negative review, cannot verify the identity of a reviewer, and cannot use traditional customer service responses to resolve disputes in the way they would outside the marketplace. The review system determines trust for potential buyers, and the platform controls its rules and enforcement. Policies on incentivized reviews, seller responses, and review removal vary by platform and change over time, often without advance notice.

Customer data access is perhaps the most commercially significant area of platform control for sellers thinking about long-term business building. On most marketplaces, the buyer's personal information, email address, purchase history, and contact details belong to the platform, not the seller. The seller fulfills the order but does not gain a customer they can market to directly. On Amazon specifically, sellers receive a shipping address but are explicitly prohibited from using customer contact information for marketing purposes. This means that every sale on a marketplace is a transaction without a customer relationship, unless the seller builds mechanisms to bridge that gap through owned channels.

Fee structures and payment terms are set by the platform and can change. Amazon's referral fees, FBA fulfillment fees, advertising costs, and storage fees have all increased over time, and sellers who have built their margin models around a specific fee structure carry exposure to those changes. For resellers with thin margins who depend on marketplace volume for the majority of their revenue, a fee structure change can meaningfully alter the economics of the entire business.

How Do the Major Marketplace Categories Differ in Their Marketing Dynamics?

Marketplaces are not uniform in structure, and the marketing and operational dynamics differ significantly by category. Understanding the specific platform you are operating on is prerequisite knowledge for building an effective strategy within it.

Retail and product marketplaces, led by Amazon but including Walmart Marketplace, eBay, Etsy, and similar platforms, are primarily discovery and transaction environments. Marketing within these platforms centers on listing optimization, sponsored product and brand advertising, review accumulation, and pricing strategy. The advertising systems on these platforms, particularly Amazon Advertising, have matured significantly and now offer sophisticated targeting, audience, and attribution capabilities within the marketplace ecosystem. The challenge is that the data these systems generate is largely confined to the platform: Amazon attribution tracks what happens inside Amazon but does not connect to what happens on the seller's own website, email list, or other channels.

B2B and wholesale marketplaces, including Alibaba, Faire, and industry-specific platforms, operate on longer sales cycles and higher transaction values, which changes the marketing dynamics. Discovery is still platform-controlled, but the buyer journey involves more direct communication between buyer and seller before a transaction occurs. Relationship management within the platform, response time to buyer inquiries, and the quality of product specifications and catalog content are more significant marketing levers than in consumer retail marketplaces.

Service and vertical marketplaces, including Thumbtack, Houzz, Angi, Zillow, and similar platforms, connect service providers with buyers in categories like home improvement, real estate, and professional services. These platforms typically sell leads to service providers rather than facilitating direct transactions, which creates a different cost structure and attribution challenge. The lead generation model means that the platform controls the top of the funnel but not the conversion, and the quality of leads varies significantly by platform, category, and geography. Marketing outside the platform, through Google Ads, SEO, and owned channels, remains essential because marketplace leads alone are rarely sufficient for the volume and quality required to sustain a service business.

App stores, primarily Apple's App Store and Google Play, represent a unique marketplace category because the platform controls not only discovery and transaction but also the technical distribution infrastructure. App developers are entirely dependent on platform approval for their product to reach users, and platform policies around in-app purchases, subscription structures, and data collection directly affect the business model. The 30% commission structure on in-app purchases that both platforms have historically charged has been the subject of significant regulatory scrutiny in multiple jurisdictions, including EU proceedings under the Digital Markets Act.

Gig economy platforms, including Uber, Airbnb, Fiverr, and Upwork, represent a form of two-sided marketplace where the service provider is the seller and the platform mediates the entire relationship, including pricing in some cases. For providers operating on these platforms, the marketing challenge is primarily internal: building visibility and reputation within the platform's ranking and review system, rather than driving external traffic to a listing.

How Should Sellers Structure Advertising Across Marketplace and Owned Channels?

One of the most common strategic errors marketplace sellers make is treating marketplace advertising and owned channel advertising as separate programs with separate objectives. They are not. They are parts of the same customer acquisition system, and the most effective approach treats them as such.

Within the marketplace, advertising investment directly affects the signals the platform's ranking algorithm uses to evaluate listings. Sponsored product campaigns on Amazon, for instance, drive immediate sales velocity, which feeds back into organic ranking as a positive signal. This means that within-marketplace advertising has a compounding return that goes beyond the direct revenue from sponsored sales: it builds the organic rank that drives unsponsored visibility over time. Sellers who treat marketplace advertising purely as a cost center, without accounting for its impact on organic ranking, are systematically undervaluing it.

Outside the marketplace, the objective of advertising is to build a customer relationship that the marketplace itself cannot provide. Driving traffic from Google Ads, Meta, or other owned channels to a product listing on Amazon generates a sale but does not capture a customer. Driving traffic to an owned landing page, capturing an email address, and then directing the customer to the marketplace for the transaction captures both the sale and the beginning of a direct relationship that can be developed independently of the platform.

This dual-channel approach, sometimes called a marketplace plus direct model, is the structural answer to the data ownership limitation of marketplace selling. The marketplace provides reach and transaction infrastructure. The owned channel provides customer data, remarketing capability, and independence from platform algorithm changes. Neither is sufficient alone for a seller who wants to build a durable business rather than a platform-dependent one.

The advertising attribution challenge in this model is significant. A customer who sees a Meta ad, visits an owned landing page, and then purchases on Amazon is a conversion that no standard attribution system will connect end to end without deliberate infrastructure. The Meta ad gets no credit because the conversion happened on Amazon. Amazon sees the sale but does not know the customer came from Meta. The owned landing page visit is visible in site analytics but not connected to the downstream purchase. Building the attribution infrastructure to connect these touchpoints requires custom tracking implementation, UTM parameter consistency, and in some cases direct API integration with marketplace platforms to pull sales data that can be matched against upstream marketing activity.

What Data Do Marketplaces Provide and What Are the Gaps?

The data available from marketplace platforms varies significantly by platform and by seller tier, and understanding both what is available and what is missing is essential for building a realistic measurement framework.

Amazon provides sellers with a substantial set of reporting tools through Seller Central and, for advertising, through the Amazon Advertising console. Sales data is comprehensive: units sold, revenue, return rates, and Buy Box percentage are all available at the product level. Advertising data includes impressions, clicks, spend, and attributed sales for sponsored campaigns. Amazon's Brand Analytics tools, available to brand-registered sellers, provide search term data, market basket analysis, and demographic insights about buyers.

What Amazon does not provide is buyer-level data in a form that allows direct customer relationship building. The email addresses of buyers are not available to sellers for marketing purposes. Post-purchase remarketing to Amazon buyers through external channels requires the buyer to have interacted with the seller's owned properties independently. This data gap is the central limitation of Amazon as a channel for sellers who want to build owned customer relationships alongside marketplace volume.

The Amazon Marketing Cloud (AMC) is a data clean room environment that allows advanced advertisers to perform custom analyses on Amazon's anonymized, event-level data. AMC enables multi-touch attribution analysis across Amazon advertising touchpoints, audience overlap analysis, and custom audience building, all within a privacy-compliant framework that does not expose individual buyer data. For sophisticated sellers with the technical capability to use it, AMC represents the most powerful analytics environment available within the Amazon ecosystem, though it requires SQL knowledge or agency support to use effectively.

Google Merchant Center and Shopping campaigns operate similarly to marketplace advertising in some respects but with a critical difference: the transaction occurs on the seller's own website, not on Google's platform. This means that the full post-click journey is visible in the seller's analytics, conversion tracking is under the seller's control, and the customer data generated by the transaction belongs to the seller. For sellers who can drive comparable volume through Shopping campaigns as through marketplace listings, the owned transaction model is significantly more valuable from a data and relationship-building perspective.

Meta's advertising ecosystem provides rich audience and behavioral data for top-of-funnel targeting and remarketing, but its attribution has been affected by iOS privacy changes that limit pixel-based tracking. Server-side conversion API (CAPI) implementation has become the standard approach for maintaining measurement accuracy on Meta for sellers who drive traffic to owned properties. For sellers driving traffic from Meta to marketplace listings, attribution is more limited because the marketplace transaction is outside Meta's measurement environment.

How Does Platform Dependency Risk Manifest for Marketplace Sellers?

Platform dependency risk for marketplace sellers operates similarly to the account-level and platform-level risks covered in the context of Google Ads account ownership and ad arbitrage, but with a higher commercial stakes because the marketplace may represent the primary or exclusive sales channel.

Algorithm dependency is the most pervasive form of marketplace risk. A seller whose organic ranking drives the majority of their sales is exposed to any algorithm change that affects how listings are evaluated and ranked. Amazon has made significant changes to its ranking algorithm over time, including increasing the weight of recent sales velocity relative to historical performance, changing how reviews from specific geographies are weighted, and adjusting how fulfillment method (FBA versus FBM) affects ranking. Each of these changes has materially affected individual sellers' visibility without any action by the seller themselves, as noted in the context of platform trust in our piece on platform trust and risk in arbitrage models.

Policy change risk on marketplaces is significant because the platform can change the rules under which sellers operate with minimal notice and limited recourse. Amazon's periodic enforcement actions against review manipulation, listing policy violations, and intellectual property complaints have resulted in account suspensions and listing removals that have disrupted or terminated seller businesses. The appeal process for marketplace account actions is notoriously slow and inconsistent, and the absence of a direct contractual relationship with a human counterpart at the platform makes escalation difficult.

Account ownership on marketplace platforms mirrors the Google Ads account ownership question covered in our previous piece on Google Ads account ownership in reselling models. On Amazon specifically, seller accounts are tied to the business entity and email address used at registration. Resellers operating on behalf of brands or within franchise or supplier arrangements need to understand who owns the marketplace seller account in the same way they need to understand who owns their Google Ads account. A reseller who has built significant sales history and review volume in a marketplace account they do not own faces the same transition risk as one operating in a supplier-held ad account.

Concentration risk is the aggregate effect of over-dependence on a single marketplace. Sellers who generate 80% or more of their revenue through a single marketplace have effectively made their business dependent on the decisions of a single platform entity. Fee increases, algorithm changes, category restrictions, and account-level issues all carry existential consequences for a business at that level of concentration. Building revenue diversification across multiple marketplaces, alongside direct-to-consumer channels, is the structural risk management response, even if the diversified channels are less efficient individually than the primary marketplace.

How Do You Connect Marketplace Activity to Owned Reporting and Attribution?

Connecting marketplace sales data to the broader marketing and attribution infrastructure of a business is one of the more technically demanding challenges in modern performance marketing, and it is one that the majority of marketplace sellers have not fully solved. The gap between what happens inside the marketplace and what is visible in owned analytics and reporting environments represents a blind spot that affects budget allocation, channel optimization, and business decision-making.

The foundational requirement is a data integration layer that pulls marketplace sales data into a central reporting environment where it can be combined with data from owned channels. For Amazon sellers, this typically involves using Amazon's Selling Partner API (SP-API) to extract order data, advertising data, and inventory data on a scheduled basis and loading it into a data warehouse or BI environment. For sellers on multiple marketplaces, the same process applies across each platform's API, with normalization of data structures to allow cross-platform comparison.

Once marketplace data is in a central environment, it can be joined with data from Google Ads, Meta, email platforms, and owned analytics to build a unified view of marketing performance. A customer who was reached by a Google Ads campaign, visited the seller's website, signed up for an email list, and subsequently purchased on Amazon can be connected across those touchpoints if the tracking identifiers are passed correctly through each interaction and the Amazon order data is matched against the email address or other identifier captured earlier in the journey.

UTM parameter strategy for marketplace sellers needs to account for the fact that most marketplaces do not pass UTM parameters through to a conversion that can be attributed back. Driving traffic from paid channels to a marketplace listing and tracking it effectively requires using URL parameters that can be matched against marketplace order data through a shared identifier, such as a coupon code or a custom landing page that captures the traffic source before redirecting to the marketplace. This is not a perfect solution but it provides directional signal where none otherwise exists.

For sellers operating at scale, custom attribution models that combine marketplace data, paid media data, and owned channel data provide a more complete picture of the customer acquisition funnel than any single platform's native reporting. Building these models requires data engineering capability, a defined attribution logic, and regular reconciliation against actual revenue to ensure the model reflects commercial reality. The output is a view of marketing performance that accounts for the full path from first exposure to purchase, across platforms and channels that do not natively share data with each other.

This is precisely the type of integration and reporting infrastructure that makes the difference between a marketplace seller who knows which marketing activities are driving profitable growth and one who is optimizing based on incomplete data. It is also infrastructure that requires deliberate design: it does not emerge from standard platform implementations, and it does not appear in off-the-shelf analytics tools without custom configuration.

What Does a Mature Marketplace Marketing Program Look Like?

A mature marketplace marketing program for a seller or reseller operating across owned and marketplace channels has several defining characteristics that distinguish it from a program that is simply active on multiple platforms without intentional integration.

It has a clear channel role definition. The marketplace is for reach, transaction volume, and algorithmic visibility building. The owned channel is for customer relationship development, email list growth, and data capture. Paid media outside the marketplace drives traffic to whichever destination best serves the objective of a given campaign: marketplace listing for immediate conversion volume, owned landing page for relationship capture.

It has a unified measurement framework. Sales data from all marketplace channels flows into a central reporting environment alongside owned channel data, ad spend data, and customer lifetime value data. Budget allocation decisions are made based on a view of performance that accounts for the full customer acquisition path, not just what individual platform dashboards report.

It has a retention program that operates independently of the marketplace. Email marketing, loyalty mechanisms, and post-purchase engagement happen on the seller's own infrastructure, using customer data captured through owned channel interactions. This retention program reduces dependency on marketplace volume by building a direct audience that can be reached without platform intermediation.

It has a diversification strategy. Revenue is spread across multiple marketplaces and owned channels in proportions that ensure no single platform's decisions can threaten the viability of the business. The diversification is not just across marketplaces: it includes SEO-driven organic traffic to owned properties, email revenue, and direct relationships with wholesale or B2B buyers where applicable.

It has a data integration and attribution infrastructure that is treated as a core business asset rather than a technical project. The ability to see the full marketing picture, across platforms and channels, is what enables the decisions that compound over time into competitive advantage.

How Atabey Approaches Marketplace and Multi-Channel Operations

Building the infrastructure to connect marketplace activity to owned reporting and attribution is where the gap between knowing what to do and being able to execute it is widest. Most sellers understand in principle that they should have unified data and connected attribution. The challenge is translating that understanding into a working system that runs reliably and produces reporting that can actually inform decisions.

Atabey's data services practice is built around exactly this type of integration work. We design and implement reporting frameworks that pull data from marketplace APIs, ad platforms, CRM systems, and owned analytics environments into a unified structure where cross-channel performance can be evaluated on consistent metrics. For marketplace sellers, this typically means connecting Amazon SP-API or equivalent marketplace data sources to a central data warehouse, normalizing the data against paid media and owned channel reporting, and building dashboards that surface the metrics that matter for budget allocation and growth decisions.

The attribution layer is where this integration does its most valuable work. When a customer's journey spans a Meta ad, an email click, a marketplace listing, and a direct purchase on a seller's own site across a period of weeks, standard platform reporting shows none of that path coherently. A properly integrated data environment shows all of it, with conversion credit distributed according to a model that reflects how the business actually acquires customers rather than how any single platform would prefer to take credit.

We have worked with sellers and resellers operating across Amazon, direct-to-consumer storefronts, and multiple paid media channels to build reporting environments that provide this kind of visibility. The output is not just better dashboards. It is the ability to make media allocation decisions based on what is actually driving revenue across the full customer acquisition funnel, including the parts of it that individual platforms cannot see.

If your business is operating across marketplace and owned channels without a clear picture of how marketing activity across those channels connects to actual revenue, that is a solvable problem. See how we approach data integration and reporting for multi-channel and marketplace operations.

Frequently Asked Questions

Marketplace marketing raises specific questions about platform control, data access, and how to build measurement infrastructure that spans owned and marketplace channels. The ones below address the most common practical challenges.

How do I track which marketing campaigns are driving sales on Amazon? Amazon does not natively accept UTM parameters from external campaigns in a way that connects to order data. The most common approaches are using unique coupon codes or promotional codes tied to specific campaigns, creating campaign-specific landing pages that capture the traffic source before redirecting to the marketplace listing, and using Amazon Attribution, which is available to brand-registered sellers and provides limited cross-channel tracking for traffic driven to Amazon from external sources. For a more complete view, pulling Amazon order data through the SP-API and matching it against upstream marketing touchpoints using shared identifiers, such as email addresses captured through owned properties, provides directional attribution that standard implementations cannot.

What is the difference between Amazon FBA and FBM from a marketing perspective? From a marketing perspective, the primary difference is in how fulfillment method affects ranking eligibility and Buy Box performance. FBA listings are eligible for Prime and generally perform better in Amazon's algorithm for Buy Box assignment, particularly for competitive categories. FBM listings can be competitive in categories where FBA storage fees are prohibitive or where the seller has fulfillment cost advantages. From an attribution perspective, both models present the same data gap: the transaction occurs on Amazon's infrastructure and customer data is owned by Amazon regardless of fulfillment method.

Should I drive external traffic to my Amazon listing or to my own website? The answer depends on your objective. Driving external traffic to an Amazon listing increases sales velocity, which feeds back into organic ranking and can have a compounding effect on marketplace visibility. However, the customer data from that sale belongs to Amazon. Driving traffic to your own website captures the customer relationship, allows full attribution tracking, and builds the owned audience that reduces your long-term platform dependency. A dual-channel approach, driving some external traffic to Amazon for ranking velocity and some to owned properties for relationship capture, is the most balanced strategy for sellers who want to build both marketplace presence and direct audience simultaneously.

How do I build a customer relationship when the marketplace doesn't share buyer data? The primary mechanism is to create touchpoints outside the marketplace transaction that capture customer information voluntarily. This includes inserts in product packaging that direct customers to a registration page, warranty or product support pages that require an email address, social media presence that buyers can follow independently of the marketplace, and off-platform content like reviews, tutorials, or community engagement that builds brand affinity that exists outside the marketplace relationship. Each of these requires investment but creates owned audience data that the marketplace cannot take away when the platform relationship changes.

What APIs are available for pulling marketplace data into a central reporting environment? Amazon provides the Selling Partner API (SP-API), which replaced the older MWS API, for programmatic access to order data, advertising data, inventory data, and catalog information. Walmart Marketplace offers a similar Seller API. Etsy, eBay, and most major marketplaces provide API access to order and listing data for registered sellers. For programmatic advertising data, Amazon Advertising has its own API separate from SP-API. Aggregating data from multiple marketplace APIs into a unified reporting environment typically requires a data pipeline tool, such as Fivetran, Airbyte, or a custom ETL implementation, to handle the extraction, transformation, and loading process reliably at scale.

How does the Digital Markets Act affect marketplace sellers in Europe? The EU's Digital Markets Act (DMA) designates certain large platforms as gatekeepers and imposes specific obligations on how they treat third-party sellers and the data generated by those sellers' activity. For marketplace sellers, the most relevant provisions relate to data access: gatekeeper platforms are required to provide sellers with access to the data generated by their activity on the platform, which in principle addresses some of the data ownership gap described in this article. The practical implementation of these provisions is still evolving, and enforcement actions against non-compliant gatekeepers, including Amazon, are ongoing. Sellers operating in European markets should monitor DMA enforcement developments, as successful enforcement could meaningfully expand the data available to marketplace sellers in EU markets.

Connecting marketplace activity to owned reporting and attribution infrastructure is a data integration challenge as much as a marketing one. See how we approach data integration and reporting for sellers and resellers operating across marketplace and owned channels.