Essential metrics on third-party data usage, accuracy, privacy concerns, and why custom data solutions deliver better campaign results
The third-party data landscape is shifting beneath marketers’ feet. Usage among digital marketers has dropped from 75% to 61% in just two years, while accuracy concerns and privacy regulations continue to reshape how brands approach audience building. For companies that depend on high-volume, campaign-ready data, these changes demand a strategic response. DataPartners helps marketers build custom data solutions that outperform generic third-party lists by starting with campaign goals rather than commodity data pulls.
Key Takeaways
- Third-party data usage is declining sharply. Marketers reduced third-party data usage by 14 percentage points in two years, with 75% of brands planning to phase out reliance on it by 2026.
- Accuracy remains a critical problem. Third-party data accuracy has been reported as low as 32-69%, creating significant potential for wasted spend when marketers rely on unverified data.
- First-party strategies deliver measurable ROI. Companies using quality first-party data achieve 2.9x revenue uplift and reduce customer acquisition costs by up to 83%.
- The data broker market keeps growing despite usage decline. The global market reached $298.30 billion in 2025 and is projected to hit $603.30 billion by 2035.
- Privacy regulations are tightening worldwide. GDPR fines now exceed €7.1 billion cumulatively, with 179 jurisdictions implementing data protection frameworks.
- External data requires strong quality controls. Data quality depends heavily on sourcing, freshness, verification, processing, and how closely the audience is built around the campaign goal.
Understanding Third-Party Data: Key Definitions and Distinctions
What is Third-Party Data?
Third-party data refers to information collected by entities that have no direct relationship with the consumer. Data brokers, aggregators, and list vendors compile this data from public records, surveys, website tracking, and purchase histories, then sell it to marketers for targeting and prospecting.
The critical distinction lies in the source relationship:
- First-party data: Information you collect directly from your customers and prospects
- Second-party data: Another company’s first-party data shared through a partnership
- Third-party data: Data purchased from vendors who aggregated it from multiple sources
How Third-Party Data Differs in Quality and Reliability
The fundamental challenge with third-party data is verification. When data passes through multiple hands before reaching your campaign, accuracy degrades at each step. This creates real problems for marketers focused on marketing data quality and campaign performance.
Only 21% of companies now use third-party data to drive personalized marketing efforts, compared to 37% that rely on first-party data. This shift reflects growing awareness that commodity data often fails to deliver the targeting precision modern campaigns require.
The Data Broker Market: Size, Scope, and Scale
1. Global data brokers market valued at $298.30 billion in 2025
The global data brokers market reached $298.30 billion in 2025 and is projected to reach $603.30 billion by 2035, growing at a CAGR of 7.30%. This growth continues despite declining usage rates among marketers, indicating that data volume and applications are expanding even as quality concerns mount.
2. U.S. market dominates with $116.50 billion
The United States represents the largest single market, valued at $116.50 billion in 2025 and projected to reach $235.60 billion by 2035. North America as a region captured 41.20% of global revenues, with the U.S. accounting for approximately 94.80% of that regional share.
3. Marketing and advertising agencies lead end-user segments
Marketing and advertising agencies represented 38.22% of market share among data broker end users in 2025. This dominance reflects agencies’ ongoing need for prospect data, though many are reconsidering their reliance on generic lists in favor of custom audience solutions.
4. Consumer data segment holds 35.10% market share
Consumer data led all data type segments with 35.10% share in 2025, while health data emerged as the fastest-growing segment at a projected 13.80% CAGR through 2035. For marketers focused on B2C data solutions, this growth creates both opportunities and challenges around data quality and compliance.
5. Structured data dominates at 61.40% market share
Structured data formats held 61.40% market share in 2025, though unstructured data is growing faster at 12.60% CAGR. This preference for structured formats reflects marketers’ need for data that integrates cleanly into CRM systems, marketing platforms, and campaign workflows.
Third-Party Data Usage: The Decline in Numbers
6. Usage dropped from 75% to 61% in two years
Third-party data usage among digital marketers plummeted 14 percentage points in just two years, falling from 75% to 61%. This rapid decline signals a fundamental shift in how marketers approach audience building and targeting.
7. Only 21% use third-party data for personalization
Just 21% of companies now rely on third-party data to drive personalized marketing, compared to 37% using first-party data. The gap continues to widen as brands prioritize data sources they control and trust.
8. 75% of brands plan to phase out third-party data reliance by 2026
Three-quarters of brands have committed to phasing out their dependence on third-party data by 2026. This planned exodus reflects concerns about accuracy, privacy compliance, and the availability of better alternatives.
9. 71% of brands growing first-party datasets
The flip side of declining third-party usage is aggressive first-party investment. 71% of brands, agencies, and publishers are currently growing or planning to grow their first-party datasets, nearly double the 41% rate reported just two years earlier.
The Accuracy Problem: Why Third-Party Data Underperforms
10. Third-party data accuracy has been reported at 32-69%
Third-party data accuracy rates have been reported as low as 32-69% in various studies, creating significant waste in direct mail, email, and digital campaigns. For marketers spending substantial budgets on outreach, this accuracy gap means considerable wasted investment from the start.
11. 98% of website visitors remain anonymous without strategic intervention
Without proper first-party data collection, 98% of website visitors remain completely anonymous. Solving the anonymous-visitor problem requires the right mix of first-party collection, identity strategy, and reliable external data, not simply another generic data pull.
Data Privacy Regulations and Consumer Trust
12. GDPR fines exceed €7.1 billion cumulatively
Cumulative GDPR fines have now exceeded €7.1 billion, with €1.2 billion levied in 2025 alone across more than 330 enforcement actions. These penalties make compliance a financial imperative, not just a legal one.
13. 179 jurisdictions now have data protection frameworks
Data privacy has gone global. 179 of 240 jurisdictions analyzed now have data protection frameworks in place, covering approximately 80% of the world’s population. This regulatory expansion complicates third-party data use across borders.
14. 75% of consumers will not buy from untrusted companies
Consumer sentiment directly impacts the bottom line. 75% of consumers said they will not purchase from organizations they do not trust with their personal data. Trust built through transparent data practices translates to revenue.
15. 86% of consumers trust companies using first-party data
Companies that prioritize first-party data earn consumer confidence. 86% of consumers express higher trust in companies that rely primarily on first-party data, giving these brands a competitive advantage in customer acquisition and retention.
16. 45% of third-party apps access sensitive data unnecessarily
Security concerns extend beyond breaches. 45% of third-party applications access sensitive user information without legitimate business reasons, creating exposure that regulators and consumers increasingly reject.
First-Party Data Performance: The Superior Alternative
17. First-party data delivers 2.9x revenue uplift
The performance gap between first-party and third-party data is substantial. Businesses using first-party data achieve 2.9x revenue uplift compared to those relying on other data sources. This multiplier effect makes first-party investment a clear priority.
18. First-party personalization delivers 5-8x ROI
Marketing spend powered by first-party data personalization delivers 5-8x ROI compared to campaigns using third-party data. The accuracy and relevance of owned data translates directly to better audience targeting performance.
19. First-party behavioral data improves conversions by 73%
Using first-party behavioral data improves conversion rates by 73% compared to third-party alternatives. First-party behavioral signals give marketers valuable visibility into recent customer actions, while high-quality external data can extend that insight to prospects and audiences a brand has not yet reached.
20. First-party strategies reduce CAC by up to 83%
Customer acquisition costs drop dramatically with first-party data strategies. Organizations report CAC reductions up to 83% when shifting from third-party to first-party data approaches. The efficiency gains come from eliminating waste inherent in inaccurate third-party lists.
21. 70% of marketers report measurable ROI from first-party data
The ROI case is clear and widely validated. 70% of marketers report measurable ROI improvements after prioritizing first-party data collection and activation. This consensus makes the strategic direction obvious for serious data-driven marketing teams.
Why Custom Data Solutions Outperform Generic Third-Party Lists
22. Custom data processing dramatically improves campaign performance
The statistics paint a clearer picture: marketers are becoming more selective about third-party data. Generic, unprocessed data creates avoidable waste, while well-sourced external campaign-ready data that is cleaned, verified, and built around the campaign can still play a critical role in customer acquisition. But marketers still need external data to reach new audiences, identify movers, build prospect universes, and expand market coverage.
The solution is not abandoning external data entirely. The solution is working with a data partner that processes, verifies, and customizes data around your specific campaign needs rather than selling you a commodity list.
Custom data solutions address the core problems revealed in these statistics:
- Accuracy: Custom processing, deduplication, and verification dramatically improve accuracy beyond raw third-party rates
- Relevance: Data built around your market, geography, and campaign objectives eliminates waste from untargeted records
- Compliance: Data partners with established compliance processes reduce regulatory risk
- Integration: Campaign-ready data formatted for your specific systems eliminates preparation work
DataPartners builds custom, processed, campaign-ready data audiences that solve the problems generic third-party lists create. The approach starts with your marketing objective, not a prebuilt database, ensuring every record serves your actual campaign needs.
The Strategic Shift: From Generic Data to Campaign-Ready Solutions
The evidence across these 22 statistics reveals a fundamental transformation in how marketers approach external data. Usage is declining not because marketers need less data, but because they demand better data. Accuracy rates below 70%, regulatory fines in the billions, and consumer trust gaps have forced a reckoning with commodity list purchases.
Yet the data broker market continues growing, and marketers still require external sources for prospecting, audience expansion, and customer acquisition. The resolution to this apparent contradiction lies in differentiation: generic, unverified third-party lists are being rejected, while custom, processed, campaign-ready data solutions are becoming essential.
The most successful marketers in 2026 are those who recognize that “third-party data” is not a monolithic category. Raw data aggregated without verification creates waste. Data that is sourced strategically, matched to campaign objectives, verified through multiple processes, deduplicated, enriched, and delivered in ready-to-use formats delivers measurable ROI.
First-party data remains the gold standard for customer relationships, delivering 2.9x revenue uplift and 5-8x ROI. But external data still plays a critical role when it is treated as a strategic input requiring professional processing rather than a commodity purchase. The future belongs to marketers who understand this distinction and choose data partners accordingly.
Frequently Asked Questions
What is the primary difference between first-party, second-party, and third-party data?
First-party data is information you collect directly from your customers through your own channels. Second-party data is another organization’s first-party data shared through a partnership agreement. Third-party data is aggregated from multiple sources by vendors who have no direct relationship with the consumers, then sold to marketers for targeting purposes.
How do data privacy regulations like GDPR and CCPA impact the use of third-party data?
Privacy regulations significantly restrict third-party data collection, usage, and sharing. GDPR fines have exceeded €7.1 billion cumulatively, and 179 jurisdictions now have data protection frameworks. These regulations impose requirements around lawful data processing, transparency, consumer rights, data sharing, and in certain circumstances consent and cross-border transfers, making third-party data compliance increasingly complex and costly.
What measures can businesses take to ensure the quality and accuracy of third-party data?
Businesses should work with data partners that provide custom processing, verification, and hygiene services rather than purchasing commodity lists. Key measures include validating data freshness, requiring match and append processing to verify records, implementing deduplication, and testing sample data before full deployment. Working with partners who start with your campaign objectives rather than generic databases improves quality significantly.
How are privacy changes and reduced third-party signals changing marketing strategies?
Privacy restrictions, browser tracking limits, and broader signal loss continue to push marketers toward stronger first-party data strategies. Although Google no longer plans to eliminate third-party cookies from Chrome outright, marketers are still investing in direct data collection, customer data platforms, and reliable external data partners to reduce dependence on any single tracking method. With 71% of brands actively growing first-party datasets and 75% planning to phase out commodity third-party reliance, the industry is prioritizing owned data and processed, campaign-ready audiences built from verified sources.
Can third-party data be used ethically and effectively for audience targeting?
Yes, when sourced from reputable providers that maintain compliance standards and offer processed, verified data rather than raw aggregated lists. The key is working with data partners that prioritize accuracy, transparency, and consent-based collection. Custom data solutions that start with specific campaign needs and geographic requirements deliver far better results than purchasing generic third-party lists with unknown provenance.