Maybe the data gods don’t have us all pegged — yet.

One of the biggest data collectors and sellers, Little Rock-based Acxiom, knows all about my house, my car and my purchases of vegetable seeds. It believes I have 32 interests — 21 of which are accurate.

But its files also say that my education ended with high school, and that I’m an unmarried, childless craftsman with a truck, earning less than $30,000 — all wrong. (To be fair, Acxiom’s data on two of my colleagues were more accurate.)

Acxiom has thousands of pieces of information on nearly every U.S. consumer, the Federal Trade Commission reported last year. It has a sense of their political affiliations, charitable giving, community involvement, online and credit card purchasing habits, earnings and social media use, according to a General Accounting Office report from 2013.

Unlike some of its competitors, Acxiom allows you to go to a website, aboutthedata.com, see your data profile, and edit or delete it. (It asks your name, address, email address, date of birth and the last four digits of your Social Security number, so Acxiom can verify that you are you.)

Acxiom chief privacy officer Jennifer Barrett Glasgow said that errors in the data may reflect gifts the individual bought for others. It may put too much weight on a magazine subscription, believe a fallacious survey response, or confuse members of the same household.

“My recommendation is that you correct the data, which is what we set up the site for in the first place," Ms. Glasgow said. Then I won’t be beset by ads that don’t match my needs, she said.

John Simpson, privacy project director of Washington D.C.-based Consumer Watchdog, suggested that I consider further obscuring myself from the all-seeing eye. “You could go in and deliberately ask for corrections and screw it up” even more, he said.

It might be better to delete my hobbies but correct the factual errors, said Pam Dixon, executive director of the World Privacy Forum. Though lenders, insurers and employers are legally barred from using marketing data to make decisions, there’s no law preventing, say, colleges from considering it when they weigh admitting my kids, she said.

Ms. Glasgow countered that Acxiom’s contracts wouldn’t allow that. The data “is not to be used for any kind of eligibility decision,” she said. “It is to be used solely to market to you, or for market research purposes.

Good data eliminates ad “clutter,” she said, adding that anyone can opt out of getting targeted ads through the industry’s website youradchoices.com.

Acxiom reports that 780,000 people have viewed their profiles, with just 3 percent making changes and 3 percent opting out of the company’s filing cabinet.

A 2013 Senate Commerce Committee report found that Acxiom’s customers included “47 Fortune 100 clients; 12 of the top 15 credit card issuers; seven of the top 10 retail banks; eight of the top 10 telecom/media companies; seven of the top 10 retailers” and majorities of the big players in nine other industries.

So if the data brokers think you’re financially unsophisticated, you might get offers for high-interest credit products, said Ms. Dixon. If they have you pegged as an impulse buyer, online retailers might jack up their prices when they detect you.

Acxiom is one of a host of companies that rakes in data and sells it to marketers, who use it to decide what you get in the mailbox and see in banner ads online. The industry has claimed that it added $156 billion in revenue to the U.S. economy in 2012.

Not all data brokers are as forthcoming as Acxiom.

Minnesota-based eBureau also allows you to see your data, but demands your address, home phone number, and scans or photocopies of a government-issued ID and a recent utility or credit card bill. The firm did not respond to multiple calls and emails.

An Oracle spokeswoman declined comment on that firm’s data disclosure policies. Oracle recently bought data broker Datalogix.