Lois Beckett for ProPublica has a thorough piece on data brokers — companies that collect and sell information about you — and what they know and where they get the data from.
They start with the basics, like names, addresses and contact information, and add on demographics, like age, race, occupation and "education level," according to consumer data firm Acxiom's overview of its various categories.
But that's just the beginning: The companies collect lists of people experiencing "life-event triggers" like getting married, buying a home, sending a kid to college — or even getting divorced.
Credit reporting giant Experian has a separate marketing services division, which sells lists of "names of expectant parents and families with newborns" that are "updated weekly."
The companies also collect data about your hobbies and many of the purchases you make. Want to buy a list of people who read romance novels? Epsilon can sell you that, as well as a list of people who donate to international aid charities.
So if you're wondering why you received that catalog in the mail, it was probably because a store sold your purchase data to a broker.