What online companies know

Sometimes you want to share personal information with online companies. For example, you’ve probably shared personal data to get free email or other online services.

here’s what those companies know about you

• News and social networking sites often require registration and typically request your real name, address, and date of birth.
• Such sites often aggregate this personal information. The demographic profile that emerges helps them understand their audience.
• The demographic profile is used to sell advertising, which keeps sites cost-free for you.

What advertisers know

As users navigate online, advertisers track data about their activity—sites visited, time spent on them; which ads were seen/clicked, how many times and when.

but what advertisers “know” about you isn’t very personal

• The data tracked is not personally identifiable.
• Just as it would be impossible to pinpoint your home address from a zip code alone, advertisers don’t know who you are, where you live, or your email address—unless you tell them.
• It's not only against most privacy policies to share personally identifiable data; it may be against the law.

Many online publishers collect demographic data—such as age, gender, or city—to target more relevant ads (e.g., if you live in Florida, ads for beach towels make more sense than ads for snowshoes).

bottom line

• Advertisers know that viewers fit into geographic or demographic criteria, such as “male in Boston, age 18-35.”
• This data lets them send the relevant ads to populations most likely to be interested in their products.
• When ads are targeted in this way, your personally identifiable information is not shared with anyone.

This approach is far from new—major national magazines publish different ads in regional editions. A New Yorker won't always receive the same issue as someone in Los Angeles.

Most websites and search engines use cookies to personalize and improve your online experience. Cookies contain data that allow a website to customize content and advertising to your interests but generally do not contain personally identifiable information.

core cookie facts

• Like the chocolate chip type, most online cookies come with expiration dates.
• Most search engines delete the data associated with a cookie after a certain period of time.
• Cookies are useful for helping sites improve their services and technology; they supply companies with data about how people use sites and search engines.
• End users also reap the benefits with improved—and free—online services.
• Remember that you can manage your cookies if you are still concerned.

It's important to protect yourself online, but there are also laws that will help you. In fact, when you share personally identifiable information (e.g., for an online purchase), you're more protected than you would be offline. And kids have even higher levels of protection.

the laws

• Under the CAN-SPAM Act, you can request that an online company (e.g., one you have purchased from) stop emailing you their ads. “Real world” stores can use your credit card number and zip code to identify you and send mail through the US Postal Service.
• Under the COPPA Act, sites knowingly collecting data from children under the age of 13 must provide a public notice on their site indicating what they collect, how it is used, and whether it is shared with third parties. Unless data is used for a one-time event (e.g., for a contest or newsletter), the site must get parental consent before collecting information.