Skip to Content

Simple Behavioral Advertising



Sites where you aren’t logged in

Imagine that you decide to browse an online book-selling Web site. You don’t intend to buy anything, but you just want to read some book reviews and compare prices with books at your local bookstore. So you fire up your Web browser and take a look at a selection of photography books, cookbooks and travel guides. Days later, when you return to the site, you are greeted with a list of books that, according to the site, are "recommended just for you." They include books about photography, cooking, and travel. You also note that the ads on the page related to those topics as well. What’s going on here?

The book-selling Web site is engaging in what is known as "first-party behavioral advertising." Sites like these most commonly use cookies to track your behavior. When you first visit the site, it deposits a cookie on your computer containing a unique ID (some long string of letters and numbers like "P1L67LLMZHRF3O"). The site keeps track of the items you view, and perhaps other information as well, like how long you stay on each page and how close you come to actually making a purchase. The site stores this information in its database, linked to your cookie ID.

When you later return to the Web site, your browser automatically sends your cookie back to the site. The site looks up your cookie ID in its database, finds that you were previously viewing books about photography, cooking, and travel, and serves you recommendations and ads related to those things.

In a slightly different variation on this model, the site might ask you for a little bit of information about yourself. You might be asked to provide your zip code, age, or gender, which are then also linked back to your cookie ID in the site’s database. The site then uses the combination of this information and your browsing behavior to serve you targeted ads.

Going one step further, you might give the site your email address to sign up for its newsletter. The site may then buy data from other companies, like retail stores or other Web sites, that have previously collected your email address and may know other information about you. This extra information that the first-party site purchases also gets incorporated into your profile.

If you want to figure out whether a first-party site like the book seller is using behavioral advertising, your best bet today is to read the Web site’s privacy policy. (For tips on reading privacy policies, see GetNetWise – .) Sites with clear policies will explain exactly what information they collect about you and your browsing behavior, who they share it with, how long they store it, and how you can opt out of behavioral advertising. Unfortunately, most privacy policies are not easy to understand, so it might take a while to find the information you’re looking for (if it’s in there to begin with).

If you decide that you’d rather not receive behaviorally targeted content or ads from a particular site, check out the tips in the Controlling Your Data section to learn how you may be able to opt out.


Sites where you log in to an account

Now imagine a slightly different situation, where you’re browsing for books online and you decide to buy one. The Web site might require you to create an account before making a purchase. So you enter your information and buy the book. The next time you return to the site, you might sign in again to check on your order or do some more browsing.

Sites where you have your own user account — like the book-selling site imagined above, news sites, social networking sites, and many others – also engage in first-party behavioral advertising, with two important differences.

First, sites where you have an account may combine the information in your account with their data about your browsing behavior. So if you set your marital status to "engaged" on your social networking profile, the site might start to show you ads for wedding vendors.

Second, sites where you have an account sometimes allow you to control whether your data is collected and used for behavioral advertising . Information about any options that allow you to choose not to receive targeted ads may be found in the "Help" section, or under "My Account," or on the privacy page. Not all sites offer these controls, though – in some cases, your only option may be to block or delete cookies from the site (as described in Controlling Your Data [insert link]). In some cases, you just may not be able to opt out. And even if you can opt-out from the delivery of targeted ads, information about you may still be collected and stored.

Here’s an example from of how a site might offer an opt-out choice to users who have accounts on the site: