How do you feel about your Web-browsing activity being tracked?
During a visit to any given website -- including this one -- the average user's browser may execute a dozen or more tracking scripts, each with its own associated tracking cookie, stored on the user's computer. This enables website publishers and ad distribution networks to record a visitor's online activity and then serve up "interest-based" or "behaviorally targeted" ads -- customized messaging based on that activity.
The benefit to website producers is that targeted ads can be sold to advertisers at higher rates because, presumably, they will be more effective than the traditional banner ads that have long been used on websites. Ad networks generally do the tracking by placing a cookie on consumers' computers when they visit a participating publisher's website. The industry refers to these as "third-party cookies" because the ad network is a third party to the relationship between the user and website publisher. Users are typically unaware that they're being tracked -- and that has made the practice controversial.
[Concerned about your privacy? Check out our three-part series: The paranoid's survival guide.]
There are disagreements even among those who depend on website advertising. While digital ad networks and many website publishers push forward with the practice, some publishers remain cautious. "They get more money from more targeted ads, but they also have brand [reputation] considerations," says Justin Brookman, director of consumer privacy at the Center for Democracy and Technology. He's also co-chair of the World Wide Web Consortium's (W3C) Tracking Protection Working Group, which is developing a Do Not Track (DNT) standard for the industry.
"Do they want to be seen as enabling third party tracking?" Brookman asks. "They're a little more cautious around perceptions than are the third-party ad networks."
Here's how the practice of tracking affects both consumers and website publishers -- and what each side of the equation is doing to try to fix matters.
Whys and wherefores of Do Not Track
In 2011, Do Not Track (DNT) technology was introduced as a method to ensure user privacy. DNT is an optional browser feature that signals advertisers to not track the user's Web activity. It does this by sending an HTTP header with the syntax DNT:1 to every website the browser visits.
The W3C working group was supposed to develop a standard to define what DNT means and how ad networks should respond, but made little progress for the first two years. So while the DNT signal was eventually adopted by most major browsers, many Web publishers and advertisers have been ignoring any privacy requests sent by the signal.