In short: First-party data are the data collected directly by a company through its own channels (website, CRM, app, customer care). In 2026 they have become the mandatory foundation of marketing: companies with mature first-party data strategies grow up to 2.9 times faster than competitors and deliver 1.5x ROI, according to the joint BCG & Google research.
- Companies with mature first-party data achieve 2.9x higher revenue growth and 1.5x ROI — BCG & Google, Responsible Marketing with First-Party Data
- Over 85% of data & technology buyers say increasing first-party data use is a business priority — IAB, State of Data 2024-2025
- The global privacy-first martech market will reach $264.4 billion in 2026 — Gartner CMO Spend Survey 2024
The deprecation of third-party cookies, App Tracking Transparency (ATT) restrictions and the entry into force of the European Digital Markets Act have shifted the centre of gravity of marketing from purchased tracking to owned data. In this 2026 guide we look at what first-party data are, why they have become a strategic asset measurable in revenue, how to build a mature program and which tools to use to activate them in compliance with GDPR and the AI Act.
What are first-party data
First-party data are the information a company collects directly from the users it interacts with, through its own owned channels: website, app, CRM, e-commerce, newsletter, customer care, loyalty programs, physical stores. They include behavioural data (clicks, visits, purchases, content viewed), declarative data (preferences, registered profile, subscriptions) and transactional data (orders, average basket, repurchase frequency).
The critical difference versus third-party cookies is the direct relationship with the user: consent is managed internally, the legal basis is documented, data quality is verifiable. According to the operational definition in the IAB State of Data 2024-2025, first-party data also include data collected by technology partners acting as processors on behalf of the brand (e-commerce platforms, CDPs, marketing clouds), provided that ownership remains with the brand itself.
Data is no longer a by-product of acquisition: it is the acquisition itself. Companies building owned data estates today convert better tomorrow, because they feed attribution, personalisation and lookalike models on a certified basis — a topic directly tied to the correct measurement of attribution marketing.
Why first-party data became strategic in 2026
The end of the cookie era and the collapse of third-party tracking
After five postponements, Google removed third-party cookies from Chrome for the entirety of consumer traffic during 2025. Safari has blocked them by default since 2020 thanks to Intelligent Tracking Prevention, Firefox since 2019. iOS 14.5+ has enforced App Tracking Transparency since 2021: according to AppsFlyer, the ATT opt-in rate in EMEA remains below 25%, cutting 60-80% of the signal available for cross-app behavioural audiences. The consequence is not a gradual reduction, it is a paradigm shift: those who do not own proprietary data operate with fragmented visibility and progressively blind attribution models.
The measurable advantage: 2.9x growth
The BCG & Google Responsible Marketing with First-Party Data research analysed over 200 global brands measuring the maturity of their first-party data program along four dimensions: data strategy, technology foundation, activation and organisation. Brands with a mature program reach up to 2.9 times revenue growth and 1.5 times ROI on the same spend levers. The gap does not depend on the quantity of data collected, but on the ability to activate it across multiple channels through a CDP (Customer Data Platform) with consistent governance.
The privacy-first martech market drives investment
According to the Gartner CMO Spend Survey 2024, martech accounts for 25% of the marketing budget, with an explicit shift toward data collaboration, clean room, consent management and CDP solutions. 77% of the CMOs surveyed expect increased investment in first-party data over the next 12-24 months. The trajectory is confirmed by Deloitte Global Marketing Trends: those who have already shifted budget from paid media to data infrastructure post higher margins and more stable CAC.
First-party vs zero-party vs third-party data: the comparison table
In the privacy-first lexicon of 2026, four types of data are distinguished by origin and ownership. The table summarises validity, cost and recommended use.
The strategic read is this: zero-party and first-party are proprietary assets that appreciate over time. Second-party extends the audience in a contractualised way. Third-party remains useful only for contextual prospecting and is heading toward the margins of 2026-2027 media plans, as also explained in the official Google Privacy Sandbox documentation.
The Deep Marketing framework for building a first-party data program
The maturity of a first-party data program is built on five operational pillars. Each is a requirement, not a nice-to-have: the chain is as weak as the least developed link.
1. Professional consent management
Before collecting data you need a CMP (Consent Management Platform) compliant with GDPR, the Italian Garante Privacy and the IAB TCF v2.2. Cookiebot, OneTrust, Didomi, Iubenda are the most widely adopted solutions in Italy. The CMP is not just a banner: it is the infrastructure that tracks consent versions, purposes, legal basis and enables revocation. A symmetric and transparent “accept/reject” banner produces consent rates of 50-70% versus the 15-25% of dark patterns, which beyond being sanctionable erode trust (and therefore the CTR of subsequent emails).
2. Server-side tracking
The shift from client-side to server-side tracking (Google Tag Manager server-side, Stape, Addingwell, Cloudflare Zaraz) recovers 25-40% of events lost to ad-blockers and ITP. It is not a way to bypass consent: it requires the same legal bases, but it preserves signal quality on the advertiser side. Meta's Conversions API and Google Ads Enhanced Conversions are today effectively mandatory to keep algorithmic targeting effective.
3. Centralised CDP or Data Warehouse
Data scattered across 10 tools (Mailchimp, Shopify, GA4, HubSpot, Meta, CRM...) is not an asset: it is an incident waiting to happen. A Customer Data Platform (Segment, mParticle, Bloomreach, Tealium, Adobe CDP) or a cloud data warehouse (BigQuery, Snowflake, Databricks) unifies identity, events and profiles under a single governance. This is the step that truly unlocks the 2.9x value measured by BCG & Google: without centralisation, data stays siloed and underused.
4. Omnichannel activation with Customer Match and CAPI
Unified data is then synced to the channels: Customer Match on Google Ads, Custom Audiences via CAPI on Meta, LinkedIn Matched Audiences, TikTok Events API. Omnichannel activation enables quality audiences (active customers, high LTV, close to churn) rather than quantity: less volume, better ROAS, a more robust base for lookalike modelling.
5. Governance, measurement and AI-readiness
Finally, you need a governance model that defines who can access what, for which purposes, and how to measure the effect. 2026 measurement combines MMM (Marketing Mix Modeling), incrementality tests and first-party analytics — topics explored in depth in the ROAS, MER, LTV and CAC guide. Clean data is also the foundation for generative AI: predictive analytics models and personalised content only make sense if trained on quality first-party data.
Privacy Sandbox, AI Act and the new regulatory perimeter
Google's Privacy Sandbox offers APIs such as Topics, Protected Audiences and Attribution Reporting as partial substitutes for third-party cookies: interesting for contextual remarketing and aggregate measurement, but with lower granularity. It does not replace a first-party program, it integrates it in prospecting phases where proprietary data is not yet available.
On the regulatory front, the EU framework has tightened: GDPR (consent basis), Digital Markets Act (interoperability and gatekeepers), Digital Services Act (profiling transparency), AI Act (use of personal data for high-risk AI systems). For Italian SMEs the operational reference remains the Italian Data Protection Authority. A well-documented first-party program, with up-to-date records of processing and DPIAs where necessary, radically reduces sanction risk and effectively becomes a competitive advantage versus competitors still anchored to legacy pixels and cookies.
Recurring mistakes in first-party data programs
Collecting consent and then not activating it, unifying data in a CDP nobody uses, personalising emails to half a million inactive contacts: the most frequent mistakes in first-party programs are not technical, they are organisational.
- Data hoarding without activation: accumulating data “because one day it will be useful” generates storage costs and compliance risk without return. Every dataset must have an active, measured use case.
- Consent fatigue: asking for consent too early, too often or with aggressive UI lowers opt-in rates and erodes trust. Consent should be requested in a value context (newsletter signup, profiling for a discount, early access).
- Silos between marketing, CRM and IT: the owner of first-party data must be cross-functional. Without a C-level sponsor, the CDP remains a technical tool without a business case.
- Anxiety-inducing over-personalisation: emails that reference recent purchases in an overly “intimate” tone trigger an uncanny valley effect. Effective personalisation is useful, not surveilling.
- No CAC vs LTV balance: every euro spent to acquire a lead must be compared with the expected lifetime value. First-party data exists precisely to measure it: not doing so is waste. Deep dive: why CAC has tripled in 2026.
90-day roadmap: what to do from next Monday
A minimum realistic roadmap for an Italian SME without a structured first-party program.
- Days 1-15: audit of the current stack. List of touchpoints, tools, data collected, legal bases. CMP verification and banner update to symmetric accept/reject mode.
- Days 16-45: implementation of server-side tracking (GTM server + Meta Conversions API + Google Enhanced Conversions). 25-40% signal recovery.
- Days 46-60: CDP or data warehouse selection. Integration of the 3 main sources (CRM, e-commerce, analytics).
- Days 61-75: first activated use case: Customer Match audience of high-LTV customers synced to Google and Meta, with exclusion of the same for prospecting.
- Days 76-90: incremental measurement. First incrementality test to validate real ROAS of the new audience. Definition of maturity KPIs.
Need to turn your first-party data into revenue?
Deep Marketing designs and activates privacy-first first-party data programs for Italian SMEs and brands, from the CMP to the CDP through to omnichannel activation on Google, Meta, LinkedIn. Request a free audit of your data estate or explore our digital advertising consulting to build proprietary audiences and measurable ROI.
Frequently Asked Questions
What are first-party data?
First-party data are the data collected directly by a company through its own channels (site, app, CRM, e-commerce, stores, customer care, newsletter). They include behavioural, declarative and transactional data. Their distinctive feature is direct ownership: the company manages consent, purposes and legal basis without intermediaries, and can therefore activate them in compliance with GDPR and the Italian Data Protection Authority.
What is the difference between first-party, zero-party and third-party data?
Zero-party data are explicitly declared by the user (preferences, surveys, quizzes). First-party data are collected by the company on its own channels through interaction (behaviour, purchases, registrations). Third-party data are aggregated by external brokers and sold as pre-built segments: they are in structural decline due to cookie deprecation. There are also second-party data, namely a partner's first-party data shared through a direct agreement or a data clean room.
Are first-party data GDPR-compliant?
Yes, provided they are collected under a valid legal basis (explicit consent for marketing, contract for transactions, documented legitimate interest in limited cases) and processed according to the principles of minimisation, purpose limitation and transparency set out in the GDPR. A CMP (Consent Management Platform) compliant with TCF v2.2 and up-to-date privacy notices are minimum requirements. The Italian Data Protection Authority has published specific guidelines on cookies and tracking that define acceptable UX.
How much does it cost to implement a first-party data program for an SME?
The cost varies with complexity. An Italian SME with 5-50 employees can start with an initial investment of 5,000-25,000 euros (CMP, server-side tracking, basic CRM integration) and an operational cost of 500-2,000 euros per month (CDP or advanced CRM licences). Typical ROI materialises in 3-6 months with advertising signal recovery, better ROAS on paid channels and CAC reduction on high-value segments. The cost of not doing it — in terms of rising CPMs and blind attribution — is structurally higher.
What is the difference between CDP and CRM?
A CRM (Customer Relationship Management) manages commercial relationships: leads, opportunities, pipeline, customer service. A CDP (Customer Data Platform) unifies identity and events from all touchpoints (CRM included, but also analytics, app, e-commerce, advertising) creating a persistent customer profile activatable across marketing channels. CRM and CDP are complementary: the CRM feeds the CDP and the CDP activates CRM data on channels the CRM does not reach directly.
Does Google's Privacy Sandbox replace third-party cookies?
Only partially. The Privacy Sandbox APIs (Topics, Protected Audiences, Attribution Reporting) offer aggregated, privacy-preserving signals, but with lower granularity and match rate than cookies. They are useful for contextual prospecting and aggregate measurement, but they do not replace the deep knowledge that first-party data guarantees on already engaged customers. The winning strategy in 2026 combines Privacy Sandbox for top-of-funnel and first-party for retargeting, loyalty and lifetime value.
Sources and References
- BCG & Google — Responsible Marketing with First-Party Data (2.9x growth and 1.5x ROI)
- IAB — State of Data 2024-2025
- Deloitte — Global Marketing Trends
- Gartner — CMO Spend Survey 2024
- Google — Privacy Sandbox Documentation
- GDPR — Official EU text
- Italian Data Protection Authority
- AppsFlyer — Top Data Trends & ATT Adoption Report
