What data brokers know about you (and how they get it)

Your data has a life beyond you

Most people assume their data stays with the companies they interact with. It doesn’t.

Behind the scenes, your information is collected, combined, and sold by an entire industry most people never directly interact with: data brokers.

These companies don’t just track what you do, they build detailed profiles about who you are, what you want, and what you’re likely to do next. Your data isn’t just collected. It’s aggregated, enriched, and resold.

What are data brokers?

Data brokers are companies that:

  • Collect personal and behavioral data from multiple sources
  • Combine it into detailed profiles
  • Sell or license that data to advertisers, marketers, and other organizations

They operate largely in the background, often without direct interaction with you.

How data brokers collect your information

Data brokers don’t rely on a single source, they pull from everywhere. Common data sources include:

  • Websites and apps (tracking pixels, cookies, SDKs)
  • Retail and purchase data (loyalty programs, transactions)
  • Public records (property, court records)
  • Social media activity
  • Location data from mobile apps
  • Email and phone number matching systems

Each source provides a fragment. Together, they create a highly detailed picture. Individually, pieces of data may seem harmless. But data brokers specialize in combining them:

  • Your shopping habits
  • Your location history
  • Your income range
  • Your interests and behaviors

All linked into a single, persistent profile. This is what makes the data valuable. The more connected your identity is, the more valuable your data becomes.

Data broker ecosystem map

How your data is bought and sold

Once profiles are created, they are:

  • Packaged into segments (e.g., “frequent travelers,” “high spenders”)
  • Sold to advertisers and marketing platforms
  • Used to target campaigns and influence behavior

This can happen repeatedly across multiple companies. Your data isn’t sold once, it’s part of a continuous marketplace.

Real-world consequences

This ecosystem doesn’t just affect ads, it affects outcomes.

  • Hyper-targeted advertising – Ads become more precise and more persistent.
  • Dynamic pricing – Different users may see different prices based on their profile.
  • Increased exposure – Your data can circulate across systems you’ve never interacted with.
  • Long-term profiling – Even old data continues to influence how you’re categorized.

Why this is hard to control

Even if you:

  • Opt out of one platform
  • Delete an account
  • Clear your data in one place

Your information may still exist:

  • In other databases
  • In previously sold datasets
  • In derived or inferred profiles

Once data is aggregated, it becomes difficult to fully unwind.

The key insight: Value comes from connection

Data brokers don’t just want data. They want connected data.

  • The same email across services
  • The same phone number across accounts
  • The same identity across contexts

That’s what allows them to build rich, valuable profiles.

How to reduce your data's value

You can’t fully stop data collection. But you can reduce its usefulness. By breaking the connections between your activities. When identities are separated:

  • Profiles become incomplete
  • Data becomes harder to match
  • Value decreases significantly

Fragmented identities lead to fragmented data and fragmented data is far less valuable. The best way to fragment this data is with MySudo®, an easy-to-use data privacy app that helps you compartmentalize all your online activity. Click here to learn more.