In the age of oversharing, what don't companies know? Google reads your emails, Facebook promotes ads based on your interests, Amazon predicts what you'll buy, and even newcomer Pinterest knows what you want for your wedding.
It's estimated that American consumers spend 35.3 hours per month online, with one out of every five minutes spent on social networking sites. The rest of that time is presumably split between shopping, researching, reading, watching videos, gaming and more.
Each of these online activities is an opportunity for companies to mine data about you.
For example, after reading this, you may decide to share this article on Facebook and Twitter and search Amazon for books on online privacy. Tomorrow, your Gmail account and Facebook may show ads for online security software, you may receive a paid tweet for anti-spyware services, and Amazon could email recommendations on popular books about the Internet and privacy. It's a general example, but it clues you in on how your actions can ripple out to your entire online experience.
With much of our personal information willingly and publicly shared, companies use this data to give us what they think we want and need. Here at CreditKarma.com, we're firm believers in the safety and privacy of your online information, and wanted to share with you what you should know about online companies while cruising the Internet this very moment.
1) "They know what you're going to buy before you do." Target recently came under fire for exposing a young girl's pregnancy to her father when the retailer predicted her pregnancy based on her recent purchases, and mailed her a catalog for expectant mothers. Target's so-called "pregnancy prediction" score sounds unsavory, but it's not uncommon. Many retailers use complex algorithms to identify shopping patterns and categorize people into certain customer profiles based on purchases, and use that to push more relevant ads to you.
While retailers have always kept records on customer shopping habits, two factors have changed the game: The technology to analyze patterns and predict behavior, and the traceability of online shopping. Sites have tools that give insights into trends and preferences about you as part of a larger consumer demographic. For example, if you're buying cocoa butter lotion and prenatal supplements, retailers like Target may soon send you ads for strollers and cribs.
Online retailers can also drop browser cookies -- markers that identify specific users and track browsing activities -- as consumers shop online. Based on that data, a site can show you ads it predicts will appeal to you even as you're browsing other sites. As you're reading news on Yahoo!, you could see sales from luxury goods website Gilt on the sidebar, as prompted by your splurges there last week.
2) "They know about your financial troubles." Banks and lenders can data-mine social media networks for financial information on consumers, from your financial woes to your recent pay raise. How? Well, you just tweeted about it.
Your public tweets, Facebook statuses and Tumblr posts are fodder for banks, lenders and anyone looking for telltale financial indications about you. Ken Lin, CEO of CreditKarma.com, wrote a Mashable article explaining that banks and lenders could be looking for changes in your financial circumstances, what your friends' financial standing is, and upcoming life changes like a marriage or divorce. It's a prime opportunity to learn about your finances and tailor marketing efforts toward you. For example, tweeting about your latest bankruptcy could trigger an issuer to show advertisements for a secured card; on the other hand, tweeting about your 720 credit score could trigger ads for rewards and travel credit cards.
Not surprisingly though, social media hasn't affected the underwriting process; banks and lenders won't deny you a mortgage if you tweet about your poor credit score. However, it could affect opportunities with future employers, as evident in recently exposed hiring practices in which employers demanded Facebook passwords from their employees.
3) "They'll change the whole website according to you." One of the more beneficial perks of the Internet is the high degree of personalization it yields. Knowing your preferences and habits means sites can also tailor your user experience to your liking. For example, flash deal and deep discount sites like Gilt and Groupon have dozens of variations of their daily email tailored to different profiles of customers.
Here at CreditKarma.com, we take every measure to protect your financial information while we also tailor the website experience based on how you interact with different components of the site. A consumer interested in saving money and a consumer trying to build their credit score are going to have two very different experiences at CreditKarma.com.
The more you shop at online retailers or use websites, the more they "learn" your interests to cater specific deals and coupons you're most likely to be interested in. Even Facebook's privacy settings, as hotly contested as they've been, passively saves your preferred settings as you interact with the site to make it as convenient as possible for you the next time you visit.
"In the end, consumers should be aware that any public information is fair game in this economic environment, and social media may be the newest cautionary landscape," Lin writes.
As our online activity inhabits a gray area where public intersects with private, the onus is ours to protect ourselves.
Remember that all the information we share, no matter how innocuous, can be a marker of your financial, demographic or consumer profile. It shapes your online experiences from what advertisements you'll see, to how a website will be presented to you and, of course, to what your professional and personal peers think of you.
In short, follow an altered version of your mother's advice: If you can't tweet anything nice, don't tweet anything at all.
Justine Rivero is the Credit Advisor for CreditKarma.com, a free credit management website that helps more than 5 million consumers access their truly free credit score and free credit monitoring.
Originally published on Forbes.